CAD FR Tutorial

CADD PRIMER
A Free Book on Computer Aided Design and Drafting (CADD).
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CADD PRIMER (Condensed version)
This condensed version of CADD PRIMER is intended to give you an overview of Computer
Aided Design and Drafting (CADD). It contains only selected topics from CADD PRIMER and it
does not include any diagrams. For a better understanding of CADD refer to CADD PRIMER:
available at http://www.caddprimer.com or contact the publisher listed below to order the book.
CADD PRIMER publication data:
Publisher’s Cataloging-in-Publication
(Provided by Quality Books, Inc.)
Duggal, Vijay.
CADD primer : a general guide to computer aided
design and drafting : CADD, CAD / Vijay Duggal. -- 1st
ed.
p. cm.
Includes bibliographical references and index.
LCCN: 99-74579
ISBN: 0-9629165-9-5 (pbk.)
1. Computer-aided design. 2. Computer graphics.
I. Title.
TA345.D84 2000

620'.0042'0285
QBI99-500469
MARC

CADD PRIMER is available at 30% off the cover price when you order directly from the publisher
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…Thank you.
Thank

Author:
Vijay Duggal:
Architect with extensive experience using CADD, New York.
Member:
American Design Drafting Association (ADDA)
US National CAD Standard committee
CAD Society

Technical Editors:
Al Zoli
Sella Rush

Reviewers and Contributors:
Prof. Eden Muir: CAD department, Columbia University
Mr. Robert Mertz: CAD class, New York Institute of Technology
Prof. Bruice M. Coleman: CAD class, Syracuse University
Dr. Jens Pohl: CAD Research Center, California Polytechnic State University
Mr. Emille Griffing: American Design Drafting Association
Mr. David Byrnes: CAD systems magazine
Mr. Richard Todd: CAD class, New York University
Mr. James Wilson: CADD/GIS Technology Center, US Department of Defense

Acknowledgments:
Editors, reviewers and contributors
Friends and family
Hardware and software vendors listed in this book

What others are saying about CADD PRIMER
Mr. David Byrnes, CAD Systems Magazine (June 2000 issue):
"CADD Primer is a fine introduction to the field of computer-aided drafting and
design. Its discipline-independent, platform-independent and programindependent coverage has something for everyone, from the prospective
Pro/E modeller on her Unix workstation to the prospective FormZ designer on
his Macintosh. And if you’re no longer a “prospective” CADD user yourself,
you probably know someone who’s starting out in the field. Do them—and
maybe yourself—a favour, and give them a copy of CADD Primer."
Mr. Tony Zilles: Editor CADinfo.net magazine (Oct. 2000 issue:
“The CADD Primer is an ideal book for high school or college-level study of
CADsystems. It is also suitable for those considering CAD for work or hobby
use but who are confused or intimidated by the technology and the jargon that
goes with it. The CADD Primer contains all the information that very quickly
becomes second knowledge to those who use CAD systems on a regular
basis. Most "old hands" learned the information the CADD Primer contains
over many years. For the new recruit, the body of "must-have" basic
information presents a great hurdle within itself, even before learning a
particular CAD program and the discipline that you intend to use it with. All the
basic information anyone could need is available, accessible and affordable in
the CADD Primer. Highly recommended.”
Prof. Eden Muir, Director of Computer Sequence, Columbia University:
“It is a useful and clear guide for a general introductory course which is not
product-specific.”
Prof. Q. Jeffrey Ge, Asst. Prof. State University of New York:
“I enjoyed reading the book. The material is well organized and clearly
explained in layman terms.”
Prof. Bruce M. Coleman, CAD class, Syracuse University:
“This book would be helpful to any individual seeking knowledge about
CADD, regardless of a formal training program.”
Mr. James Wilson, CADD/GIS center, US Department of Defense:
“This is a good manual to use as a guide to teach someone with no CADD
experience, the basic concepts of CADD. It is best when it is used before an
actual application has been purchased. It meets its intended goals for its
audience.”
See detailed reviews at http://www.caddprimer.com.

Preface
Welcome to the world of Computer Aided Design and Drafting (CADD).
CADD PRIMER is designed to teach you all the skills necessary to learn
CADD in a successful and professional manner. It assumes that you have
very little experience with computers; however, you are familiar with basic
geometry and the concept of drafting.
CADD software is commonly used for drafting architectural and engineering
drawings and for making technical illustrations of any kind. If you are a
professional associated with design or drafting or would just like to widen your
knowledge about CADD applications, then CADD PRIMER is for you.
CADD enables you to prepare fast and accurate drawings. It provides
flexibility to change drawings with minimal effort. In recent years, many
professionals have switched to CADD to enjoy the benefits of this precise and
creative tool. Today, many educational institutions include CADD as part of
their academic curriculum. As a result, CADD knowledge has become very
important to all professionals involved in the field of design and drafting.
There are a variety of systems and programs available in the CADD industry
and new programs are frequently introduced. It has become very confusing to
select a system and learn all the applications and techniques of CADD.
Design and operation of CADD programs differ from system to system, and
time spent in learning one system may not prove very useful on another.
CADD PRIMER does not focus on a specific CADD program. It provides
general information that is applicable to all the leading CADD programs, such
as AutoCAD, MicroStation and Cadkey. CADD PRIMER can give you a head
start in learning CADD, regardless of whatever CADD program you may have
to use.

Who can benefit from CADD PRIMER:
• Students associated with drawing.
•
•

Design or drafting professionals who would like to get a quick overview of CADD.
A novice or scholar who always wondered how the drawings are created using a
computer!

Important note:
CADD PRIMER is not a “how-to” book. Although it uses examples from leading CADD
programs, they are intended to illustrate general principles only.
CADD PRIMER is a beginner’s reference book on CADD.

Table of Contents
Note:
Not all the topics listed below are included in the condensed version on
CADD PRIMER. For complete understanding of CAD refer to CADD
PRIMER available at http://www.caddprimer.com

Introduction
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CADD Hardware and Software
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2.

Key Terms in this Chapter
What is CADD?
What to Expect from CADD
A Look at the CADD Industry
The Focus of this Book
How to Use CADD PRIMER

About this Chapter
Hardware and Software Overview
CADD Hardware
CADD in a Network Environment
CADD Software
CADD User Interface

1-1
1-2
1-2
1-4
1-9
1-10
1-13

The CADD Basics
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About This Chapter
Components of a CADD Drawing
Beginning to Draw
Locating Points Accurately
The Coordinate System
The Formats to Enter Coordinates
User-Defined Coordinate System
A Prototype CADD Drawing
What if You Made a Mistake?
When to Save the Drawing or Quit
Automatic Data Saving Features
CADD Filing System
A Word about Data Security
Getting Help

2-1
2-2
2-2
2-3
2-9
2-10
2-12
2-13
2-14
2-14
2-15
2-15
2-16
2-17
2-18

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2.

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About this Chapter
The Drawing Tools of CADD
Using Line Types
Drawing Multiple Parallel Lines
Drawing Flexible Curves
Drawing Arcs and Circles
Drawing Ellipses and Elliptical Arcs
Adding Text to Drawings
Defining a Text Style
Drawing Dimensions
Writing Dimensions with Different Units
Setting Dimension Styles
Adding Hatch Patterns to Drawings
Drawing Symbols
Drawing Arrows
The Artistic Side of CADD
AutoCAD, MicroStation and Cadkey Terms

3-1
3-2
3-2
3-3
3-4
3-5
3-6
3-9
3-11
3-14
3-14
3-17
3-18
3-19
3-20
3-20
3-21
3-21

View Displays
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2-18

The Drawing Tools
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4.

AutoCAD, MicroStation & Cadkey Terms

About this Chapter
The View-Display Functions
Displaying a Full View
Moving the View
Zoom-in and Zoom-out
Enlarging View by Indicating a Window
Saving and Displaying Views
Displaying Previous Views

4-1
4-1
4-1
4-4
4-5
4-5
4-5
4-6
4-7
4-7

The Edit Functions
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About this Chapter
The Role of Edit Functions
Selecting Objects to Edit
Erasing Drawing Objects
Moving Drawing Objects
Copying Drawing Objects

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5-1
5-2
5-2
5-3
5-4
5-5

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The Concept of Layers in CADD
Creating Layers for an Engineer’s Office
The Tools to Work with Layers
Are Layers Absolutely Necessary?

6-1
6-1
6-3
6-4
6-6
6-8

Introduction to 3D
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5-7
5-7
5-14
5-21
5-23

Working With Layers
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Changing Drawing Appearance
Using Edit Functions as a Drawing-Aid Tool
Steps to Draw an Engineer’s Office
Steps to Complete the Engineering Complex

About this Chapter
Why 3D?
Pictorial Views Concept
Oblique Views
Isometric Views
Steps to Draw an Isometric
Isometric Drawing-Aid Functions
3D Modeling
Working with 3D Coordinates
Steps to Draw a 3D Model
Displaying Views
3D Drawing-Aid Functions
Shading and Rendering

7-1
7-2
7-2
7-2
7-3
7-4
7-5
7-6
7-9
7-10
7-13
7-16
7-21
7-24
7-25

Printing and Plotting
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About this Chapter
The Printing and Plotting Process
Steps to Plotting
Printers and Plotters

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8-1
8-2
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8-8
8-10

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Maximizing CADD
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About this Chapter
Streamlining CADD Drawing Environment
The Design Applications of CADD
Integrated Systems
Collaborating CADD Projects on the Internet
CADD Artificial Intelligence (AI) Resources

9-1
9-2
9-2
9-6
9-8
9-9
9-10

CADD Industry Resources
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About this Chapter
CADD Industry Terms
Product Selection Criteria
Leading CADD Products
Important CADD Resources on the Internet

10-2
10-2
10-3
10-4
10-13

Introduction

Contents

i

What is CADD?

ii


ii

Presentations
Flexibility in Editing
Units & Accuracy Levels
Storage and Access of Drawings
Sharing CADD Drawings
Project Reporting
Engineering Analysis
Computer Aided Manufacturing (CAM)
Design
Add-on Programs

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i

Introduction

Note:
This condensed version of CADD PRIMER is intended to give you an overview of CADD.
It includes only important topics from CADD PRIMER. It does not include any diagrams.
CADD PRIMER includes more than 100 diagrams that illustrate the working of CADD. For
complete understanding of CADD refer to CADD PRIMER. This complete book is
available for download for $9.95 at http://www.caddprimer.com or you can order printed
copies through the publisher listed at the end of this chapter.

Term

Description

Attributes
CAD

Descriptions of electronic drawing elements.
An acronym for Computer Aided Design. It synonymously used for Computer
Aided Drafting.

CADD
CADD
system
CAFM
CAE
CAM
Command
Database

An acronym for Computer Aided Design & Drafting.
A computer system that enables you to perform drawing and design tasks.

Function
Menu
Parametric
design

An acronym for Computer Aided Facility Management
An acronym for Computer Aided Engineering
An acronym for Computer Aided Manufacturing
A single instruction issued by the user to complete a task on the computer.
A stored collection of data that can be retrieved and organized in different
ways.
A task in a program that can be completed by issuing a set of commands
through the program.
A collection of functions or commands that are displayed on the screen. You
can make selections from the menu with a pointing device such as a mouse.
A computer capability that links graphics on the screen with automated
calculations and vice versa.

i

Introduction

What is CADD?
When we think of Computer Aided Design and Drafting (CADD), certain
questions arise that we never think of while working on the drawing board. We
do not use the essential drawing board tools: paper, pencil, T-square, compass,
eraser or scale, yet still have to design or make a drawing. When even one of
these tools is missing we know how aggravating it can be. With CADD we don’t
need even one of them!
CADD is an electronic tool that enables you to make quick and accurate
drawings with the use of a computer. Unlike the traditional methods of making
drawings on a drawing board, with CADD you can sit back in an easy chair and
create wonderful drawings just by clicking the buttons of a keyboard. Moreover,
drawings created with CADD have a number of advantages over drawings
created on a drawing board. CADD drawings are neat, clean and highly
presentable. Electronic drawings can be modified quite easily and can be
presented in a variety of formats.
A decade ago, CADD was used only for specific engineering applications that
required high precision. Due to CADDs high price, only a few professionals
could afford it. In recent years, however, computer prices have decreased
significantly and more and more professionals are taking advantage of CADD.
There are hundreds of CADD programs available in the CADD industry today.
Some are intended for general drawing work while others are focused on
specific engineering applications. There are programs that enable you to do 2D
drawings, 3D drawings, renderings, shadings, engineering calculations, space
planning, structural design, piping layouts, plant design, project management,
etc. There is a CADD program for virtually every engineering discipline you can
think of.
CADD is primarily intended for single-line drafting. It has very limited
capabilities to create artistic impressions. However, CADDs 3D and rendering
features are fascinating. You can create a 3D model of an object and view it
from any angle. With proper shading and rendering, it can be made to look
picture perfect!

You can do amazing things with CADD that you never thought possible while
creating drawings with a pen or pencil. The following are some of the important
capabilities that make CADD a powerful tool:

•
•
•
•
•
•
ii

Presentations
Flexibility in editing
Units & accuracy levels
Storage and access for drawings
Sharing CADD drawings
Project reporting

CADD PRIMER: http://www.caddprimer.com

•
•
•
•

Engineering analysis
Design
Add-on programs

Presentations
You can create fine drawings with hundreds of colors, line types, hatch patterns,
presentation symbols and text styles. Even if you dont like something about
your presentation after you have finished it, you can quickly change it. It takes
only a few simple steps to change the text style, color or line type and you can
print a fresh copy of the drawing.
There are a number of ready-made presentation symbols and hatch patterns
available in CADD that can be used to enhance the look of drawings. For
example, a site planner can add tree symbols, shrubs, pathways, human figures,
and other landscape elements to create a site plan. Similarly, an architect can
use ready-made symbols of doors, windows, furniture, etc., to make a
presentation.
In addition to preparing impressive presentations on paper, you can use CADD
to make on-screen presentations. You can plug your computer into a projector
and present your ideas on-screen. Advanced CADD programs even allow you to
created animated images. You can illustrate how a building would appear while
walking through it, or how a machine would function when different machine
assembly parts operate.

Flexibility in Editing
CADD provides the flexibility to make quick alterations to drawings. You can
erase any portion of a drawing with pinpoint accuracy. It takes only seconds to
do a job that could take hours on a drawing board. In many cases, you won’t
even have to erase the drawing to make the change. You can rearrange the
existing components of the drawing to fit new shape. This enables you to
analyze design options with minimal effort.
The following are some of the editing capabilities of CADD:

•
•
•
•
•
•
•

Move or copy drawing elements
Enlarge or reduce parts of a drawing
Add one drawing to another
Stretch a drawing to fit new dimensions
Make multiple copies of a drawing element
Change the size and style of text
Change units of measure, accuracy and style of dimensions

iii

Introduction

Units & Accuracy Levels
CADD allows you to work with great accuracy. If you need to create highly
accurate geometrical shapes, CADD is the answer. It can help avoid timeconsuming mathematical calculations.
You can work with different units of measure, such as architectural units,
engineering units, scientific units and surveyor’s units. These units are
represented in standard formats commonly used by professionals.
Example:

When working with engineering units, you can specify whether all
the dimensions should be represented in inches, feet-inches,
centimeters or meters. Similarly, you can choose angular units of
measurement such as decimal degrees, minutes, seconds or
radians.

You can set an extremely high accuracy for the units of measurement. You can
work with as high precision as 1/1000th of an inch! However, such accuracy is
seldom required. You will often need to set the CADD program to a lesser
accuracy to avoid unnecessary fractions.
In general, when you need to work on a large scale drawing such as a plan of a
township, you may want to set a lesser degree of accuracy, say 1’-0". The
computer will round off all the measurements to the next foot and you won’t see
any fractions less than a foot. When you need to work on a minute detail, you
can set a higher degree of accuracy such as 1/8th or 1/64th of an inch.

Storage and Access of Drawings
It is quick and convenient to organize CADD drawings in a computer. You can
have thousands of drawings on a computers hard disk and can open any one of
them within seconds.
A computers electronic filing system has the following advantages over the
traditional filing system:

•
•
•

It enables you to create a highly organized environment
It contributes to savings in working space
An electronic drawing never gets old and faded. Any time you need a
drawing, you can print a new copy from the disks.

Sharing CADD Drawings
The electronic drawings can be shared by a number of users, allowing them to
coordinate projects and work as a team. This is accomplished by connecting
different computers via a network.
Example: In a building project, different professionals such as architects,
engineers and construction managers can use the same set of
electronic drawings to coordinate building services. If a change is

iv


made to the drawings, this information becomes available to all the
team members automatically.
With the use of modems and the Internet, it has become far easier to share
information. Most architects and engineers these days share drawings
electronically.
You can also publish your drawings on the Internet and collaborate CADD
projects using a web site. Many CADD programs include special functions that
allow you to export drawings in a format that can be viewed on the Internet.
Refer to Chapter 9 "Maximizing CADD" for more information on collaborating
CADD projects on the Internet.

Project Reporting
The computer can be used to prepare project reports such as records of areas,
quantities and cost estimates. Using the database capabilities of CADD, you can
link non-graphic information (such as text or value) with the graphic elements of
the drawing. The non-graphic information is stored in a database, which can be
used to prepare reports.
Example: An architect can link text attributes associated with the symbols of
doors and windows in a drawing. The attributes can describe the size
of the door, material, hardware, cost, etc. Later on the computer can
automatically prepare a door schedule listing all the doors and
windows in the drawing.
The non-graphic information is directly linked with the drawing objects. When a
change is made to the drawing, the values in the reports are updated
automatically. This provides a useful means to manage large projects.
There is a special category of software called Computer Aided Facility
Management (CAFM) designed for building management. These programs
allow you to import drawings from CADD programs and link attributes to them to
form a database. The database can be used to keep track of spaces, areas,
costs, people, equipment, furniture, building maintenance schedule, etc..
See Chapter 10 "CADD Industry Resources" for a list of CAFM software.

Engineering Analysis
There is a separate category of programs called Computer Aided Engineering
(CAE) that can use CADD drawings for engineering analysis. The CAE
programs have a number of applications in structural design, civil engineering,
mechanical engineering and electrical engineering.
Example: A structural engineer can use a CAE program to test the design of
structural components in a building. The engineer can instantly
analyze the impact on structural members when a different load is
applied to the structure or the spacing between the members is
changed. Similarly, there are programs for mechanical engineers to
test machine assemblies. The mechanical engineer can create a

v

Introduction

prototype electronic model and test it without building a physical
model.
The advanced engineering programs even provide the ability to link calculations
with the CADD drawings. This capability is known as parametric design" that
allows the computer to automatically update the drawings when the associated
calculations are changed and vice versa.

CADD extends its power to yet another branch of engineering called Computer
Aided Manufacturing (CAM). CAM is a common method of manufacturing used
by large corporations. CADD and manufacturing programs are often integrated
into one system called CAD-CAM. These systems import CADD drawings into
CAM programs to automate the manufacturing process.
Example: An engineer can draw a machine part using CADD. The CADD
drawing is brought into a computer aided engineering (CAE) program
for engineering analysis. When the design is finalized, the drawing is
brought into a CAD-CAM system that uses numerical data from the
CADD drawing for actual manufacturing.

Design
CADD provides a convenient means to create designs for almost every
engineering discipline. It can be used for architectural design, landscape design,
interior design, civil and surveying, mechanical design, electrical engineering,
plant design, industrial design, duct design, electronic circuit design, plumbing
design, textile design and product design.
CADDs drafting capabilities provide ample means to create a design scheme.
You can create designs with great accuracy and have the flexibility to easily edit
them. This allows you to quickly prepare design alternatives.
In addition to the drafting capabilities of CADD, there are special programs that
can analyze designs or even create new ones. These programs use artificial
intelligence to "think" and make design decisions.
The design capabilities of CADD are available only in advanced CADD
programs. There are only a few such programs available. Design programs are
usually not generic. They often need to be custom-written to accomplish a
specific task. See Chapter 9 "Maximizing CADD" for discussion on design
programs.

Add-on Programs
There are a number of separate programs available that can enhance the power
of CADD. The add-on programs work as an extension of CADD to accomplish
specific tasks. Today, there are hundreds of add-on programs available for
popular CADD programs.
An architectural add-on program can allow you to instantly draw symbols of
doors, windows, kitchens, bathrooms, staircases, etc. A shading and rendering

vi


program can be used to enhance the look of 3D images. A plumbing design
program includes special functions to draw pipes, drains and plumbing joints. A
civil engineering program includes special features to work with contours and
land development; the list goes on and on.
Most manufacturers market CADD programs in separate modules. They sell a
basic drafting module for a certain price with the options to add on other
modules. There are a number of add-on programs available from independent
vendors as well.

There are hundreds of CADD programs available in the CADD industry today.
Most of them are simply drafting programs, while some offer certain engineering
analysis, design or database capabilities. Some programs are more elaborate
than the others are.
Refer to CADD PRIMER for details.

With so many CADD programs available, it is impossible to learn each one.
Most programs have similar drawing capabilities, but the exact procedures are
quite different. You may be an expert on one program and yet not know much
about another. This is because different CADD programs use different
terminology and procedures to accomplish the same tasks. It may take you
quite some time to learn the intricacies of a particular CADD program.
CADD PRIMER is designed to give you a head start in learning CADD
regardless of any program you may have to use. It describes the general
principles and applications of CADD that are applicable to most of the
programs. Its objective is to familiarize you with all the aspects of working with
CADD. Once you understand what individual functions do and which functions
to use where, you can apply this knowledge to any CADD program.
The following are the main objectives of CADD PRIMER:

•
•
•
•
•

To present an overview of CADD and describe its applications in different
fields.
To describe common terms associated with CADD hardware and software.
To outline the basic principles associated with CADD and to demonstrate
common drafting techniques and shortcuts used by professionals.
To introduce the advanced capabilities of CADD and how they can be used
to increase productivity.
To provide information about the CADD industry resources.

vii

Introduction

CADD PRIMER is a reference book. The examples in this book are illustrated in
a generic way, because our objective is not to focus on a specific program. The
examples used in this book are intended to give you an idea of how CADD
works and what it can do for you. To learn about a specific program, you will
have to obtain literature specific to that program.
A look inside CADD PRIMER...

Chapter
Chapter 1:
CADD Hardware and
Software

Chapter 2:
CADD Basics

Description
Gives an overview of CADD hardware and describes the
terminology associated with the equipment.
Presents an overview of CADD functions and describes
their role in CADD and how they are organized in various
menus.
Teaches you how to communicate with CADD through
different means of data entry.
Instructs you on the basic drawing concepts of CADD.
You will start with a simple drawing exercise.
Explains the essential features of CADD, such as how to
enter distances using different coordinate methods. You
will learn how to use Absolute, Relative and Polar
coordinates.

Chapter 3:
The Drawing Tools
Chapter 4:
View Displays
Chapter 5:
The Edit Functions
Chapter 6:
Working with Layers

viii

Presents guidelines on setting up a prototype CADD
drawing. You will learn how to save and manage CADD
drawings.
Gives you a closer look at all the drawing capabilities of
CADD. You will learn different methods for drawing lines,
arcs, polylines, text, dimensions, etc.
Describes how View-Display functions are used to
display different views of a drawing. You will learn how to
zoom in on portions of the drawing and how to save and
restore selected views.
Describes the application of CADDs edit functions. You
will learn a number of shortcut methods to fix errors. You
will also learn how easy it is to make changes by using
the erase, copy and move functions. Includes a number
of exercises to illustrate functions.
Discusses the use of layers in CADD drawings. This is a
commonly used technique that enables you to organize
your drawings better by grouping information on specific
layers.


Chapter
Chapter 7:
Introduction to 3D

Chapter 8:
Chapter 9:
Maximizing CADD
Chapter 10:

Description
Gives an overview of 3D functions of CADD. You will
learn basic 3D drawing techniques.
Describes how to make isometrics and perspectives,
enter 3D coordinates, and display 3D views from
different angles.
Describes CADDs plotting and printing procedures. You
will learn how to print the same drawing with a number of
variations. Includes a discussion on plotting and printing
machines.
Presents an outline of advanced features of CADD, such
as the use of attributes to make project reports, the use
of macros to do automated tasks, applications of design
and database, and how CADD works in an integrated
environment with other programs.
Presents an outline of important features offered by
leading CADD programs and the guidelines to choose a
CADD system.
Includes a helpful CADD directory listing the leading
CADD programs and important resources on the
Internet.

CADD PRIMER ordering information:
CADD PRIMER is available at 30% off the cover price when you order directly from the publisher at
the address listed below or through the web site http://www.caddprimer.com/discount30.htm.
Note: We do not take orders over the phone or by fax. You may place your order directly on-line or
send your payment by mail.
$10
Download:
secured web site. Or, you can send $9.95 to Mailmax Publishing and we
will send you an URL to download the book. Please include your E-mail
address.
Thank you.

ix

CADD Hardware
and Software

1

Contents
About this Chapter

1-1


1-2


1-2

CADD Hardware

1-3

System Unit
External Storage Devices
The Monitor
Digitizer, Puck and Mouse

1-3
1-4
1-4
1-4
1-5

A Typical CADD Network

1-5

CADD Software

1-6

Draw
Edit
Data Output
Data Storage and Management
System Control
Special Features

CADD User Interface
Using the Menu Bar
Entering commands in the command window
Using the tool buttons
Using the dialog boxes
Working in the drawing area

1-6
1-6
1-7
1-7
1-7
1-8
1-8

1-8
1-8
1-8
1-8
1-8

1-i

CADD Hardware and
Software

Note:

About this Chapter
This chapter provides a general overview of CADD hardware and software.
There are three main topics in this chapter:

•
•
•

CADD Hardware
CADD Software
CADD User Interface

CADD Hardware describes the physical components of a CADD system such
as system unit, memory and hard disk. It introduces the requirements and
specifications necessary for CADD equipment.
Note:

If you are familiar with computers, you may want to browse through
the CADD Hardware topic to re-familiarize yourself with information
referred to in later chapters. If you are unfamiliar with computers, you
should read the entire topic before proceeding.

CADD Software describes the main functions of a CADD program, such as
drawing, editing, data output, system control, data storage and management
and other special features.
CADD User Interface describes how to interact with CADD by various means
of data entry. You will learn how commands are entered using the menus,
keyboard, toolbars, etc.

1-1


Term

Definition

Bit, byte,
megabyte (MB),
gigabyte (GB)
Data exchange
format (DXF)
Digitizer
Dots per inch (dpi)
Dot-pitch
Graphical user
interface (GUI)
Hardware
Mainframe system
Megahertz (MHz)
Minicomputer
PC
Resolution
Server
Software

A bit is the smallest unit of electronic memory. The second
smallest unit of memory is a byte, which contains 8 bits.
One megabyte contains one million bytes. 1000 megabytes
make one gigabyte.
A standard format used to exchange electronic drawings
between different CADD programs.
An electronic data input device.
A specification of printers and plotters that determines how
accurately they can print.
The distance between the picture elements (pixels) on the
screen.
An environment established by the program that uses
graphic clues to help the user communicate with the
computer.
The physical components of a computer.
Large computer that processes data at very fast speeds and
has a lot of memory. Used by large organizations.
The speed of data processing. The speed of one million
cycles per second is called 1 MHz.
Smaller version of the mainframe system. Also used by
large organizations.
Personal computer, also know as a microcomputer.
The sharpness of the image on the screen.
A computer dedicated to running the network program, with
computers connected via a network.
The programs that run on the computer.

There are two parts of a computer system, hardware and software, and a
CADD system is no exception. Computer hardware is the physical
components of the computer such as system unit, monitor and plotter.
Computer software is the program that determines the application of a
system.
There are three main categories of computers with respect to hardware:

•
•
•

1-2

Mainframe
Minicomputer
Microcomputers, for example personal computers (PCs)


Mainframe computers have a lot of data processing power and their size is
quite big. A single mainframe computer performs all the data processing and
is accessed via terminals connected to it. Minicomputers are smaller versions
of mainframe computers. Microcomputers (PCs) are the desktop or laptop
computers of today and are used for individual computing needs.
There are two main categories of computer software:

•
•

System software
Application program

The system software manages the internal operations of the computer. The
application programs are tools that help you accomplish your work, such as
CADD. (This topic is further described in CADD PRIMER)

CADD Hardware
The following are the main hardware components of CADD:

•
•
•
•
•
•

System unit
Ø Central processing unit
Ø Memory
Ø Hard disk, floppy disk, CD-ROM
External storage devices
Monitor
Printers and plotters
Keyboard
Digitizer, puck and mouse

System Unit
The system unit is the computer that is used for all data processing. The
main components of the system units are the central processing unit (CPU)
and memory. In mainframe and minicomputers CPU and memory are usually
separate compartments that house thousands of devices. In todays PCs,
however, they all fit in a small box commonly known as a desktop computer.
Most desktop computers today come equipped with a hard disk, floppy disk
drive and CD ROM. Lets have a look at the components of a system unit:
Ø Central processing unit
Ø Memory
Ø Hard disk, floppy disk, CD-ROM
Note: The above topics are described in detail in CADD PRIMER.

1-3


External Storage Devices
There are a number of external storage devices available such as magnetic
tapes, zip drives and removable hard disks. They are commonly used to keep
backup copies of electronic files for safekeeping.
Magnetic tapes are quite common for storing large volumes of data. A
magnetic tape that looks like a small videocassette can store thousands of
megabytes of data. However, they are quite slow and require a lot of time to
store or retrieve data.
Zip drives were introduced recently; they use zip disks to store data. A zip
disk is like an upgraded version of floppy disk that can store about 100MB of
data. They are particularly helpful if you plan to use CADD or other graphic
programs that generate quite big data files. You can store an entire project on
one zip disk that could take 50 or more floppy disks.
Another new option for data storage is the removable hard disk. You can
remove the entire hard disk from your computer and use it on another
computer. This approach is commonly used when you need to work on
different computers and you want the same information to be available
instantly.

The Monitor
The monitor is the computer screen and is used to display information. A
good monitor is very important for CADD in order to display fine graphics. A
color monitor is essential because many CADD drawing techniques are
based on colors. Monitors are available in various sizes ranging from 13" to
30" or more. Today, average monitors have the ability to display millions of
colors.
The main factor that determines the quality of a monitor is the resolution. The
term resolution refers to sharpness of an image displayed on the screen.
Resolution is measured by the number of picture elements (pixels) that a
screen can display. The more pixels and the closer they are, the sharper the
image. The distance between pixels is called the "dot-pitch". The smaller the
dot-pitch, the sharper the image. A .26 or smaller dot-pitch monitor is
recommended for CADD applications.

CADD drawings are printed using fine-quality printers and plotters. Drawings
are neat and clean and as accurate as the naked eye can see. You can print
drawings at as much as 1200-dpi (dots per inch) accuracy. This means 1200
dots are printed in a one-inch-long line! All the text, dimensions, and other
graphics are printed highly accurate, neat and crisp. You can print drawings
with a lot of variations; for example, drawings can be printed with different
sizes, line types, text fonts and colors.
There are a variety of printers and plotters available in the computer industry.
They work on different principles and their prices vary significantly. There are

1-4


many types of pen plotters, ink-jet printers, laser printers and plotters,
electrostatic printers, etc.
Printers and plotters range in cost from as little as $200 to as much as
$20,000. The less expensive ones are not as accurate and are commonly
used for rough prints. Professional drawings, however, are printed only by
using fine printers and plotters. For more information on printers and plotters,
refer to Chapter 8 Printing and Plotting.”

Digitizer, Puck and Mouse
The digitizer (also known as a graphic tablet) and the puck are the data input
devices most commonly used in CADD systems. These devices allow you to
enter point locations on the screen and to make selections from the menus.
As the puck is moved over the surface of the digitizer, it moves the indicator
(cursor) on the screen relatively. To enter a point, you need to position the
cursor at the appropriate position on the screen and then press the "Enter"
button on the puck.
Digitizers are available in many sizes and styles. Fig. 1.3 (available in CADD
PRIMER) shows an example of a digitizer used with CADD. A number of
commands are printed on the digitizer surface. To enter a command, place
the puck over the desired command and press the "Enter" button. The
selected command is instantly entered. The puck buttons are configured to
perform many other tasks. For example, one button is used to make
selections, another to enter the data, another to return to the previous menu
and another to cancel the last command.
A mouse is another pointing device that can be used with CADD. Like the
puck, the mouse allows you to control the position of the cursor on the screen
by rolling it across a flat surface, but it does not require a digitizer. Some
programs support working with a mouse only, while others support both the
mouse and the digitizer. A mouse is much cheaper than a digitizer or puck,
but provides only limited data entry options.

A Typical CADD Network
A number of CADD workstations can be connected together by using a
computer network. A computer network provides the ability to share both
equipment and information. A CADD network is not only cost effective but it
provides a great convenience in sharing information.
All the drawings and data can be stored in a common storage medium, which
is accessible to all users. You can open any drawing from any workstation in
the network and share it with others. This is impossible if computers are not
connected in a network.
Note: This topic is further described in CADD PRIMER.

1-5


CADD Software
A CADD program contains hundreds of functions that enable you to
accomplish specific drawing tasks. A task may involve drawing an object,
editing an existing drawing, displaying a view of the drawing, printing or
saving it, or controlling any other operation of the computer. The functions
contain a number of commands that enable you to specify exactly what you
want to do and how you want to do it.
The functions are organized into modules that provide easy access to all the
commands. The program is divided into modules such as draw, edit, data
output, function control, data storage and management. A program may also
have a number of specialized functions such as layers, database and 3D.
Lets have a look at the CADD modules:

•
•
•
•
•
•

Draw
Edit
Data output
System control
Data storage and management
Special features

Draw
The draw module provides access to all the drawing functions of CADD.
Whenever you need to draw something this group of functions is used. The
draw module enables you to draw lines, arcs, circles, ellipses, text,
dimensions, symbols, borders and many other drawing components.
Draw is CADDs most frequently used module because all drawing work is
accomplished using it.

Edit
The edit module lets you change existing drawing elements and manipulate
them in a number of ways. You can move, copy or erase drawing
components. You can enlarge or reduce the sizes of diagrams or change the
color and line type of drawing components. You can also change the size and
style of text and dimensions, as well as edit a dimension to show different
units of measurement. A good CADD program is designed to change the
appearance of all drawing elements created with CADD.
The edit functions also act as convenient drawing-aid tools. They enable you
to join missing corners of lines, trim drawing components along a line, stretch
them to fit a new shape, etc. The list of editing capabilities goes on and on.
The edit functions make CADD a dynamic drawing tool.

1-6


Data Output
The data output module enables you to display drawings on the screen and
then print them on paper. There are two separate sets of functions that help
accomplish this:

•
•

View-display functions
Print/plot functions

The view-display functions allow you to display different views of a drawing
on the screen. These functions are used quite often, because every time you
need to draw something or edit something, you need to focus on that portion
of the drawing. With the help of view-display functions, you can zoom in on a
specific portion of the drawing.
The print and plot functions allow you to print drawings using a printer or a
plotter. You can control many aspects of printing and plotting. You can print
the same drawing in different sizes by applying the appropriate scale factor.
You can plot the drawings with specific colors, pen thickness, and line types.

Data Storage and Management
The data storage and management module allows you to store and manage
drawing data. Through the use of the functions in this module, you can store
drawings as files on the hard disk. You can manage the files in directories
and sub-directories, and move, copy or delete them as needed.
CADD data management functions also let you translate drawings created by
other CADD programs. These functions convert drawing data to a generic
format that can be read by any CADD program. Data exchange format (DXF)
is one of the common data translation formats used by CADD programs.
There are a number of data exchange formats available.

System Control
The system control module (also known as system defaults) allows you to
control how CADD works. CADD programs are designed for a broad range of
professionals, including architects, designers, engineers and surveyors. With
the help of system control functions, you can set the working environment of
CADD to suit your needs.
Example: You can set the type of units that you will be using, the accuracy
of the units, a style for dimensions and text, colors, layers, line
type in a drawing, etc. Additionally, you can customize screen
menus, the display of colors on the screen, resolution of the
screen, size, the speed of the cursor, etc.
You can also specify whether the selected defaults should apply to a single
drawing, to a specific project, or to all the projects in a specific category. The
defaults can be set on a temporary or permanent basis.

1-7


Special Features
CADD programs usually offer a number of special features that make working
with CADD easier and allow you to automate many drawing tasks. For
example, you can create layers in a drawing that allow you to segregate
drawing components. You can develop spreadsheets and databases that can
be used to create many types of project reports. You can create threedimensional (3D) drawings, such as isometrics and perspectives, with the
help of 3D functions. You can also accomplish many other automated tasks
with the help of macros.
The number of special features a CADD program has or how elaborate they
are varies from one program to another. Some vendors sell specialized
features as separate packages, while others include them in a single
package. It all depends how a program is written, how big or small it is, and
how it is sold.

CADD User Interface
CADD user interface provides the environment and the tools that allow you
and the computer to communicate. Each CADD program establishes an
environment that best suits its purpose. The goal is to make working with
CADD efficient. Most programs use a Graphic User Interface (GUI) to
communicate with the user. The GUI provides visual aids for quick data
entry. You are given tools to select functions, enter textual or mathematical
data, locate points in the drawing window, select objects in the drawing
window, etc.
The following are the most common ways to communicate with CADD.
Refer to CADD PRIMER for details.

Using the Menu Bar
Entering commands in the command window
Using the tool buttons
Using the dialog boxes
Working in the drawing area

1-8


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1-9

The CADD Basics

2

Contents
About this Chapter

2-1


2-2


2-2

Beginning to Draw

2-3


2-3

Cartesian Coordinates
Polar Coordinates

2-3
2-3


2-4


2-4


2-5

What if You Made a Mistake

2-5


2-5


2-6

CADD Filing System

2-6


2-6

Getting Help

2-7


2-7

2-i

The CADD Basics

Note:
This condensed version of CADD PRIMER is intended to give you an overview of
CADD. It includes only important topics from CADD PRIMER. It does not include any
diagrams. CADD PRIMER includes more than 100 diagrams that illustrate the working of
CADD. For complete understanding of CADD refer to CADD PRIMER. This complete
book is available for download for $9.95 at http://www.caddprimer.com or you can order
printed copies through the publisher listed at the end of this chapter.

About this Chapter
This chapter provides an overview of CADD functions. It describes what various
functions will accomplish, how they are organized into CADD menus and how to
use them.
You will learn to use basic functions to draw lines or circles, enter text, etc. A
brief exercise walks you through the use of these functions. You will also learn
how to measure distances and how to locate exact points. This chapter
illustrates how to use coordinate methods, such as absolute coordinates, relative
coordinates and polar coordinates to measure distances.
In addition, this chapter highlights important principles in setting up CADD
drafting standards. It demonstrates how to set up a prototype CADD drawing for
a quick start.
Finally, this chapter shows you how to save drawings and where to store them.
In this section, you will learn about data saving functions and safety measures to
prevent data loss.

2-1


Term

Description

Absolute coordinates
Aperture
Cartesian coordinates
Object snaps
Origin point
Polar coordinates
Prototype drawing
Relative coordinates
User-defined coordinate
system

Distances measured from a fixed reference point.
Effective diameter of the cursor on the screen.
A rectangular system of measurement to locate points in the
drawing area.
A method for indicating point locations using existing drawing
objects as a reference.
The 0,0 location of the coordinate system.
A system to locate the points using an angle and distance.
A template drawing that has a number of preset defaults.
Distances measured from the last location of the cursor.
A mode of measurement that allows the user to set up a
customized coordinate system.

CADD drawings are created by drawing individual components (also called
drawing objects or entities) of the drawing such as lines, arcs, dimensions and
symbols. On a drawing board, you may not notice how many lines and arcs you
need to complete a diagram, but with CADD you need to be specific. You need
to specify exactly what you want to draw and how you want to draw it. Consider
this scenario: drawing a square with rounded edges. Using a drawing board, you
would quickly draw four lines and round off the edges with a template. Using
CADD to draw the similar square, you will have to draw four lines and four arcs
separately. You must specify where each line and arc starts, where it ends, the
center point of the arc, the radius, etc. (Illustrated with Fig. In CADD PRIMER)
CADDs drawing functions are used to create each component of a drawing
such as lines, arcs, circles, ellipses, symbols, text, dimensions pointers,
polylines, borders and patterns. You can complete most of the drawings by
using these components of CADD.
To draw any component of the drawing, you need to access a particular function
from the Draw menu. There are separate functions to draw text, dimensions,
patterns, symbols, and other elements of a drawing. To draw a symbol, such as
an octagon, you don’t need to draw each side one by one. The Symbol function
allows you to instantly insert a symbol into the drawing. Similarly, when you
need to draw hatch patterns, borders, or arrows, separate CADD functions
enable you to do that.
Drawing a component is quite straightforward. When you enter a command, the
corresponding menu displays a prompt that guides you through steps to take. To
complete a task, you will need to enter data using the keyboard, make
selections from sub-menus, and enter points with the help of a pointing device
to indicate where you want to position a drawing component.

2-2

For more information e-mail mailmaxinfo@aol.com or fax (914) 614-3269

Beginning to Draw
Refer to CADD PRIMER for a basic drawing exercise.

The coordinate system is another method of locating points in the drawing area.
It enables you to locate points by specifying distances from a fixed reference
point. You can locate a point by giving its distance in the horizontal direction,
vertical direction, measuring along an angle, etc. (Illustrated with Fig. In CADD
PRIMER)
The coordinate system is available when a function requires data input in the
form of point locations. You may use it while drawing, editing or any time you
need to locate a point. The most common coordinate systems are as follows:

•
•

Polar coordinates

Note:
The method of entering coordinates varies from one program to another. For
example, in AutoCAD, the coordinates can be entered directly in the command
window with the keyboard. In MicroStation and Cadkey, special dialog boxes let
you enter the coordinates.

Cartesian coordinates is a rectangular system of measurement that enables you
to locate points with the help of horizontal and vertical coordinates. The
horizontal values, called X-coordinates, are measured along the X-axis. The
vertical values, called Y-coordinates, are measured along the Y-axis. The
intersection of the X- and Y-axes is called the origin point, which represents the
0,0 location of the coordinate system. (Illustrated with Fig. In CADD PRIMER)
The positive X values are measured to the right and the positive Y values are
measured above the origin point. The negative X and Y values are measured to
the left and below. To enter a coordinate, you need to enter both the X and Y
values separated by a comma (X, Y).

Polar Coordinates
Polar coordinates allow you to define a point by specifying the distance and the
direction from a given point. This mode of measurement is quite helpful in
working with angles. To draw a line at an angle, you need to specify how long a
line you want to draw and specify the angle. (Illustrated with Fig. In CADD
PRIMER)

2-3


Cartesian or polar coordinate values can be entered in two formats:

•
•

Absolute
Relative

Absolute format is a way of measuring distances from a fixed reference location
(origin point), which is the 0,0 location of the coordinate system. Consider this
point to be stationary at all times. In some CADD programs this point remains
visible at the left bottom corner of the drawing area, while in others it is invisible.
You can use this point as a reference to measure any distance in the drawing.
Absolute coordinates are primarily used to adjust the alignment of diagrams in a
drawing, to align one drawing with another or to make plotting adjustments.
Relative format is a way of measuring distances from the last point entered. All
measurements are taken the same way as the absolute coordinates, with the
only difference being that the relative coordinates are measured from the last
point entered instead of the origin point. When a point is entered, it becomes the
reference for entering the next point and so on. This mode of measurement is
frequently used for drawing because it is always convenient to place the drawing
components relative to each other rather than a fixed reference point.

Note:
Each CADD program uses its own annotations to enter absolute or relative
coordinates. The task table located at the end of the chapter shows some
examples from leading CADD programs.

CADD allows you to create a user-defined coordinate system that can help
simplify drawing. When you need to work with a complex drawing that has many
odd angles this mode of measurement is very useful.
Lets say you need to draw or modify an odd-shaped diagram, it is very difficult
to use Cartesian or polar coordinates because they would involve extensive
calculations. In this case, you can create a custom coordinate system that aligns
with the odd angles of the diagram.
To define a new coordinate system, you need to specify where you want the
origin point and the direction of the X and Y-axis. The computer keeps working
according to this customized coordinate system unless you set it back to normal.

2-4


Important tip:
The user-defined coordinate system is especially helpful when you are working
with 3D. In a 3D drawing, you need to define each point with three coordinates
and work with various surfaces of a 3D model. The user-defined coordinate
system allows you to align coordinates with a specific surface, greatly
simplifying 3D drawing (illustrated in Chapter 7 Introduction to 3D).

A CADD program is designed to meet the needs of a vast number of
individuals. It comes with a number of options that can be customized. For
example, architects, engineers and surveyors use different annotations to
measure units and to draw dimensions. You may have a number of preferences
regarding a specific style of text, standard sheet sizes, names of layers, symbol
styles, borders, or line types to be used in a project.
When you install a CADD program, it does not have any of the defaults set as
per your requirements. You can create a prototype drawing and specify all the
defaults that you would like to use. This prototype drawing acts as a template
that can be used for all future projects.
This topic is further described in CADD PRIMER.

What if You Made a Mistake
If you make a mistake in issuing a command or in entering any data, you can fix
it without many hassles. CADD provides a very convenient way to fix mistakes.
Most CADD programs have a built-in function (commonly known as UNDO) that
instantly reverses the effect of the last command entered. Many programs allow
you to use this function multiple times, so you can go back many steps to fix the
mistakes. However, it is always better to take quick action as soon as you
realize that a mistake has been made, because the more you go forward with
the mistake, the harder it may be to fix it.

When you feel that sufficient work has been completed, you should save the
drawing. As a guideline, approximately 15-minute interval is considered
appropriate to save your work. This ensures that if you lose your drawing for any
reason, you will only lose a maximum of 15 minutes worth of work.
You can save the drawing in two ways: save the drawing with the same name or
save the drawing with a different name. When you save the drawing with the
same name, it overwrites the old information on the disk with the current
information. Before issuing this command, you must ensure that you no longer
need the old information. When you save the drawing under a different name, it
makes a copy of the drawing and leaves the original data on the disk
undisturbed.

2-5


There are times when you may not want to save a drawing at all. When you
make an irretrievable mistake, you may not want to save it. If you save, it will
replace the last updated drawing on the disk with the damaged drawing. If the
drawing seems to be damaged, it is better to just exit the drawing. You will lose
the work you did since the last time you saved it, but it may be better to revert to
the last version of the drawing.

CADD comes with a number of built-in safety features that can help safeguard
data. Most CADD programs automatically create a back-up file when you save a
drawing. The back-up file contains the original information that was in the file
before you saved it. So, if you save a drawing and later realize that you need
the earlier version, you can retrieve the original information from the back-up
file.

CADD Filing System
The computer stores information in blocks of data called files. Each drawing
created with CADD is stored as a separate data file. Similarly, if you create
documents using other programs such as a word processor or spreadsheet, then
these too are stored as separate data files.
In addition to data files, system software and application programs have
hundreds of files of their own. The computer can be used to store and manage
thousands of files depending on the available memory. To manage a large
amount of files, good file organization is very important.
Files are organized in directories that make it easy for you to locate them. A
directory is like a file folder that may contain any number of files. Subdirectories can be created within a directory that can be used to store groups of
files. Each file is identified by its name, directory and sub-directories.

The most important task while working on a computer is to safeguard data. Data
may be lost due to any number of reasons. Your hard disk may be damaged or
data on it may be corrupted. You may forget to save your work and turn off the
computer. You may erase a file when you meant only to move or copy it. A
computer just follows instructions and takes action in a split second. You can
lose hundreds of files within seconds just by pressing a wrong button.

2-6


The most important way to safeguard data is to organize your data and take
preventive measures. You need to develop standards for naming and organizing
files and directories. You need to create directories and sub-directories to store
different projects. You need to segregate old work from new work and classify
files according to dates, projects, user names, etc.
Make back-up copies of whatever you do. After each working session, store
your work on floppy disks as well as the hard disk. Keep a written record of what
the files contain. Develop a timetable for how often you will back up your entire
hard disk to a back-up tape or other storage device. Keep multiple back-up
copies according to dates and time. Store them at a remote location for
safekeeping.

Getting Help
One of the first functions you should learn when starting to work with CADD is
how to get help. Most CADD programs come with built-in help features that
quickly get you started. Getting help is as easy as typing the word Help on the
keyboard or selecting it from the menu. Most CADD programs provide help in
the following ways:

•
•

•

•

You can choose to use a basic tutorial, which is usually provided with the
program. This tutorial gives you a quick tour of all the functions in the
program.
You can display an index that lists all the commands available in the
program in alphabetical order. You can view topics on any of the commands
listed in the index. These topics display the basic capabilities of the
command and the steps required completing it.
You can usually access task-based help in on-line help provided with the
program. Most modern programs also provide context-sensitive help, such
as help with dialog boxes, which provides the information you need when
you need it.
You can consult the printed user guides and reference manuals, which are
nearly always provided with the program.

This topic lists important terms used in leading CADD programs. Refer to CADD PRIMER for
details.

2-7


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2-8

The Drawing
Tools

3

Contents
About this Chapter

3-1


3-2


3-2

Using Line Types

3-2


3-3


3-3


3-3


3-4


3-4


3-5

Drawing Dimensions

3-5


3-6

Drawing Symbols

3-6

Drawing Arrows

3-6


3-6

3-i

The Drawing Tools

Note:
This condensed version of CADD PRIMER is intended to give you an overview of CADD. It
includes only important topics from CADD PRIMER. It does not include any diagrams. CADD
PRIMER includes more than 100 diagrams that illustrate the working of CADD. For complete
understanding of CADD refer to CADD PRIMER. This complete book is available for download
for $9.95 at http://www.caddprimer.com or you can order printed copies through the publisher
listed at the end of this chapter.

About this Chapter
This chapter focuses on the two-dimensional drawing functions of CADD. It
describes in detail how to draw each element of a drawing. You will learn the
unique characteristics of different drawing elements that make them suitable for
specific drawing tasks.
In this chapter you will learn the following:

•
•
•
•

How to create line types such as dotted lines, dashed lines, multi-lines and
splines.
How to draw arcs, circles and ellipses.
How to write text and dimensions with different styles and how to control
various aspects associated with them such as size, fonts and units.
How to make drawings presentable using drawing annotations such as
symbols, arrows, borders and hatching patterns.

3-1


Term
Associative
dimensions
Benchmark
Spline
Hatch patterns
Justification
Polyline
Tangent

Description
A mode of dimensioning that automatically updates dimension values
when the dimension size is changed.
A reference point from where all distances are measured.
A flexible curve that can be drawn to fit any shape.
Ready-made patterns that can be added to a specified area in a
drawing.
The alignment of text strings in a specific direction such as to the right,
left, or center.
A string of lines that may contain a number of line segments connected
together.
A point on a circle that forms 90° angle between the center point of the
circle and another point outside the circle.

The following are the basic drawing tools found in a CADD program:

•
•
•
•
•
•
•
•
•
•

Line types
Multiple parallel lines
Flexible curves
Arcs and circles
Ellipses and elliptical arcs
Text
Dimensions
Hatch patterns
Polygons
Arrows

Using Line Types
There are a number of line types available in CADD that can be used to
enhance drawings. There are continuous lines, dotted lines, center lines,
construction lines, etc. (Illustrated with Fig. In CADD PRIMER)
CADD enables you to follow both geometrical and engineering drawing
standards. You can use line types to represent different annotations in a
drawing. For example, an engineer can use line types to differentiate between
engineering services in a building plan. One line type can be used to show
power supply lines, while the others to show telephone lines, water supply lines
and plumbing lines.

3-2

The drawing tools

CADD is preset to draw continuous lines. When you enter the line command
and indicate a starting point and end point, a continuous line is drawn. If you
want to draw with another line type, you need to set that line type as the current
line type. Thereafter, all the lines are drawn with the newly selected line type.

CADD allows you draw parallel lines simultaneously just by indicating a starting
point and an end point. These lines can be used to draw something with heavy
lines or double lines. For example, they can be used to draw the walls of a
building plan, roads of a site map, or for any other presentation that requires
parallel lines.
Most programs allow you to define a style for multiple parallel lines. You can
specify how many parallel lines you need, at what distance and if they are to be
filled with a pattern or solid fill. (Illustrated with Fig. In CADD PRIMER)
A number of add-on programs use multiple lines to represent specific drawing
features. For example, an architectural program has a special function called
”wall’. When you use this option, it automatically draws parallel lines
representing walls of specified style and thickness.

Note:
Multiple lines are a unified entity. Even though double lines are drawn, they are
treated as one line. You cannot erase or edit one line separately. However,
there are functions available that can break the entities apart.

CADD allows you to draw flexible curves (often called splines) that can be used
to draw almost any shape. They can be used to create the smooth curves of a
sculpture, contours of a landscape plan or roads and boundaries of a map.
To draw a flexible curve, you need to indicate the points through which the
curve will pass. A uniform curve is drawn passing through the indicated points.
The sharpness of the curves, the roughness of the lines and the thickness can
be controlled through the use of related commands. (Illustrated with Fig. In
CADD PRIMER)

CADD provides many ways to draw arcs and circles. There are a number of
advanced techniques available for drawing arcs and circles, which can simplify
many geometrical drawing problems. You can draw an arc by specifying
circumference and radius, radius and rotation angle, chord length and radius,
etc.

3-3


Arcs are drawn so accurately that a number of engineering problems can be
solved graphically rather than mathematically. Suppose you need to measure
the circumference of an arc, just select that arc and the exact value is
displayed.

The following are basic methods for drawing arcs and circles:
(These are essentially the same methods you learn in a geometry class.
However, when drawing with CADD the approach is a little different.)
•
•
•
•
•
•

Center point and radius
3 points
Angle and radius
2 points
2 tangents and a point
3 tangents

Note: The above topics are illustrated with Figs. in CADD PRIMER.

Ellipses are much easier to draw with CADD than on a drawing board. On a
drawing board, you need to find the right size template or draw a series of arcs
individually to draw an ellipse. With CADD, all you need to do is specify the size
of the ellipse.
The following are two basic methods for drawing ellipses:

•
•

Length and width
Axis and rotation angle


CADD allows you to add fine lettering to your drawings. You can use text to
write notes, specifications and to describe the components of a drawing. Text
created with CADD is neat, stylish and can be easily edited. Typing skills are
helpful if you intend to write a lot of text.
Writing text with CADD is as simple as typing it on the keyboard. You can locate
it anywhere on the drawing, write it as big or as small as you like and choose
from a number of available fonts.

Note:

3-4

The drawing tools

When large amounts of text are added to drawings, it slows down the screen
displays. Many programs provide options to temporarily turn off text or to
display text outlines only. This feature helps save computer memory and speeds
up the display of screen images. The text can be turned back on whenever
needed.
The following are the basic factors that control the appearance of text:
(The exact terms and procedures used vary from one program to another.)
•
•
•
•
•

Text height
Height to width ratio and inclination of letters
Special effects
Alignment of text (justification)
Text fonts


As discussed, there are a number of factors that control the appearance of text.
It is time-consuming to specify every parameter each time you need to write
text. CADD allows you to define text styles that contain all the text information
such as size, justification and font. When you need to write text, simply select a
particular style and all the text thereafter is written with that style. CADD offers a
number of ready-made text styles as well.

Important Tip:
There are a number of add-on programs available that can make working with
text faster and easier. These programs provide basic word-processing
capabilities that can be used to write reports and make charts. They provide
access to a dictionary and thesaurus database that can be used to check
spelling and to search for alternative words.

Drawing Dimensions
CADD’s dimensioning functions provide a fast and accurate means for drawing
dimensions. To draw a dimension, all you need to do is to indicate the points
that need to be dimensioned. CADD automatically calculates the dimension
value and draws all the necessary annotations.
The annotations that form a dimension are: dimension line, dimension text,
dimension terminators and extension lines (see fig.). You can control the
appearance of each of these elements by changing the dimensioning defaults.
The following are the common methods for drawing dimensions:
•
•
•

Drawing horizontal and vertical dimensions
Dimensioning from a base line
Dimensioning arcs and circles

3-5


•
•

Drawing dimensions parallel to an object
Dimensioning angles


The look of CADD drawings can be enhanced with the hatch patterns available
in CADD. The patterns can be used to emphasize portions of the drawing and to
represent various materials, finishes, and spaces. Several ready-made patterns
are available in CADD that can be instantly added to drawings.
Hatch patterns are quite easy to draw. You don't need to draw each element of a
pattern one by one. You just need to specify an area where the pattern is to be
drawn by selecting all the drawing objects that surround the area. The selected
objects must enclose the area completely, like a closed polygon. When the area
is enclosed, a list of available patterns is displayed. Select a pattern, and the
specified area is filled. (Illustrated with Fig. In CADD PRIMER)

Drawing Symbols
Symbols provide a convenient way to draw geometrical shapes. You may
compare this function with the multi-purpose templates commonly used on a
drawing board. To draw a geometrical shape, such as a pentagon or hexagon,
select an appropriate symbol from the menu, specify the size of the symbol, and
it is drawn at the indicated point. (Illustrated with Fig. In CADD PRIMER)

Drawing Arrows
Arrows (or pointers) in a drawing are commonly used to indicate which note or
specification relates to which portion of the drawing, or to specify a direction for
any reason. There are several arrow styles available in CADD programs. You
can choose from simple two-point arrows to arrows passing through a number of
points, and from simple to fancy arrow styles. To draw an arrow, you need to
indicate the points through which the arrow will pass. (Illustrated with Fig. In
CADD PRIMER)

Refer to CADD PRIMER for important terms used in leading CADD programs.

3-6

The drawing tools

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3-7

View-Displays

4

Contents
About this Chapter

4-1

Moving the View Sideways

4-1
4-2
4-2
4-2

Zooming the View to an Exact Size
Zooming Roughly by Indicating a Window

4-2


4-3

4-2
4-2

4-i

View-Displays

Note:
includes only important topics from CADD PRIMER. It does not include any diagrams.
complete understanding of CADD refer to CADD PRIMER. This complete book is available
for download for $9.95 at http://www.caddprimer.com or you can order printed copies
through the publisher listed at the end of this chapter.

About this Chapter
This chapter describes CADD’s view-display functions. These functions allow
you to display different views of a CADD drawing. They make it possible to work
on various portions of a drawing. You can move the image on the screen to
display a desired view and enlarge or reduce the images as required.

Term
Pan
Zoom in
Zoom out
Zoom factor
Viewport
Window

Description
To move the view in a specific direction.
To get a closer view.
To get a view from a greater distance.
To enlarge or reduce the view by a specific degree.
A portion of the drawing window that contains an independent view
of the drawing.
An imaginary rectangle formed by the indicated points.

4-1


CADD’s view-display functions enable you to display various views of the
drawing. You need to constantly change views in order to work on different
portions of the drawing. For example, to draw a line from one corner of a large
drawing to another, you may need to change the view two to three times. First,
you need to magnify the corner where the line is to be started, then shrink the
display to see the entire drawing and locate the other corner of the diagram, and
then magnify that corner to indicate the end point of the line.
Working with the view-display functions is similar to using a telescopic camera.
You can zoom out to view larger objects, and zoom in to get a closer view of
objects. However, CADD’s functions are much more precise and flexible. You
can magnify the drawings to an exact degree, store specific views in computer
memory, and then display them back when required.
Fig. 4.1 (available in CADD PRIMER) shows an engineering drawing of a
mechanical part. In the following examples, we will use this drawing to illustrate
the different view-display functions.
The following are the main techniques to display views. These techniques are
illustrated with diagrams in CADD PRIMER.

Moving the View Sideways
Zooming the View to an Exact Size
Zooming Roughly by Indicating a Window
Important Tips:
•

4-2

Most CADD programs automatically store all the views displayed in the drawing area.
You can instantly return to a previous view by entering a command or clicking on a
tool button.

For more info. e-mail mailmaxinfo@aol.com or fax (914) 614-3269

•

When you are finished working with one portion of the drawing and want to
display another view, you can display a full view of the drawing and then
zoom in with another window.

•

Most CADD programs allow you to display multiple views side by side. The
drawing area can be divided into different sections called viewports. You can
display a different view in each viewport. This is particularly helpful when
working with 3D drawings. For example, you can display a plan view in one
viewport, elevation in another and a 3D view in another.

This topic lists important terms used in leading CADD programs. Refer to CADD PRIMER
for details.

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4-3

The Edit Functions

5

Contents
About this Chapter

5-1


5-1


5-2


5-2


5-2


5-3


5-3

n
n

Making Multiple Copies in a Rectangular Fashion
Making Copies in a Circular Fashion

n
n
n
n
n
n
n
n
n
n

Cutting Drawing Objects Along an Edge
Drawing Parallel Lines and Arcs
Extending Drawing Objects to an Edge
Dividing an Object into Equal Parts
Making Sharp and Rounded Corners
Making Chamfered Corners
Stretching Diagrams
Enlarging or Reducing Diagrams
Rotating the Drawings
Mirroring Drawings

5-3
5-4
5-4
5-4
5-5
5-5
5-5
5-5
5-5
5-6
5-6
5-6
5-6
5-6


5-7

AutoCAD MicroStation and Cadkey Terms

5-7

5-i

The Edit Functions

Note:

About this Chapter
This chapter focuses on CADD’s editing module. The edit functions make CADD
a very powerful drawing tool and contribute to significant timesaving in design
and drafting. They provide a number of drawing shortcuts and enable you to fix
drawing mistakes.
This chapter illustrates techniques by which you can manipulate drawing
objects. It illustrates how to erase, move, copy, rotate, enlarge and reduce
drawing objects. You will also learn how to use the edit functions as a drawing
aid tool to make quick corrections.
The chapter ends with a read-through exercise that illustrates the basic steps to
draw an engineer’s office and an engineering complex plan.

Term
Array
Base point
Editing
window
Fillet
Mirror
Mirror-axis
Move

Description
A set of multiple copies of selected objects.
A reference point used as a guide to move or copy objects.
An imaginary rectangle formed by two diagonal points that is used to
select drawing objects for editing.
Joining lines or arcs at a corner.
Creating a new object that is a mirror image of an original object.
An imaginary line along which the objects are mirrored.
Moving selected objects from one place to another.

5-1


Stretch
Trim

Stretching a diagram in a specified direction.
Cutting drawing objects along a selected edge.

The edit module provides great flexibility in changing CADD drawings. If you
were to draw using only the drawing functions of CADD, it will probably take the
same amount of time as it would on a drawing board. But CADD’s editing
functions make CADD a dynamic tool that results in significant timesavings.
Changes that may look extremely difficult on a drawing board can be easily
accomplished with CADD. Even if you have to make a major change, chances
are that you won't have to redraw it from scratch. You can manipulate the
diagrams in a number of ways and may be able to rearrange the existing pieces
of the drawing to fit the new shape.
The following are the basic capabilities of the edit module:

•
•
•
•

Erasing drawing objects
Moving drawing objects
Copying drawing objects
Changing the appearance of drawing objects

In order to apply any of the edit functions, you need to select the drawing
objects that need to be edited. CADD provides a number of methods by which
you can select drawing objects. You can edit one object at a time, a group of
objects, or the entire drawing at once.
The following are the basic methods for selecting drawing objects for editing:
(The exact procedures vary from one program to another)

•
•
•
•

Selecting objects one by one
Selecting objects by enclosing them in a window
Selecting objects using selection filters
Making groups of selected objects

Note: The above topics are described in detail in CADD PRIMER.

CADD provides a fast, accurate and convenient means of erasing drawings.
Once you have entered the erase command, you are in the erase mode; any

5-2


objects you select now will be instantly erased. You can use any method
described above to select the objects.

Note:
The erase function is very powerful; it must be used with great caution. It can
erase large amounts of information within seconds. If you make a mistake while
erasing, be sure to take quick action. You can use the undo feature of CADD to
instantly disregard the effect of the last command. Do not go any further with
the mistake; it will only make it more difficult to fix the drawing.

CADD allows you to move drawing objects within a drawing in a convenient
manner. Unlike on a drawing board, you don't need to first erase and then
redraw in a new place. You can simply rearrange the existing drawing objects,
as you like. This is a very useful tool for analyzing design alternatives and
making quick adjustments to drawings.
To move the objects, the first step is to select the objects that are to be moved.
The second step is to indicate a base point. The base point acts as an anchor
for the selected objects. Finally, indicate a relocation point (or destination point).
The relocation point determines the new location of the selected objects. All the
objects are moved relative to the base point and the relocation point. Let’s say
you indicate the relocation point 4’-0” to the right of the base point. All the
selected objects will be moved 4’-0” to the right. (An exercise using the move
function is included in CADD PRIMER)

CADD allows you to make quick and easy copies of existing drawing objects.
You can copy individual drawing objects or the entire drawing all at once. You
can even make multiple copies of drawing objects within seconds.
Using the copy function is quite similar to the way the move function is used.
First, you need to select objects using any of the methods described earlier.
Then you need to indicate a base point and a relocation (or destination) point.
The copied objects are placed according to the relocation point.

Making Multiple Copies in a Rectangular Fashion
There are separate functions available in CADD that allow you to make multiple
copies in a linear or rectangular fashion (commonly known as a rectangular
array). You can make hundreds of copies within seconds. You don't need to
enter a base point and a destination point. You just need to select the objects,
specify how many rows and columns you need and the distance between them.
(Illustreated with Fig. In CADD PRIMER)

5-3


Making Copies in a Circular Fashion
CADD allows you to make multiple copies of selected objects in a circular
fashion (commonly known as a polar array). You need to enter the center point
of array, number of copies required and the rotation angle. The center point of
the array is a point around which the copies are arranged. The rotation angle
determines the extent of the rotation, and the number of copies you specify are
equally spaced between the rotation angle. (Illustreated with Fig. In CADD
PRIMER)

CADD allows you to change the appearance of drawing objects in a number of
ways. You can change the line type, color, size and style of all the drawing
objects. Using the editing functions of CADD, you can change almost every
factor that defines a drawing object.
When you enter a command to change the drawing appearance, you are
prompted to select the objects you want to change. You can select the objects
using any of the methods discussed earlier. After the selection is made, you can
specify what you want to change, and the selected objects are changed
accordingly.
The edit functions allow you to do the following:

•
•
•
•
•
•
•

Change line type, color and layer of drawing objects.
Change the radius value of arcs and circles.
Change major axis, minor axis and rotation angle of the ellipses.
Change the sharpness of curves of splines.
Change the height, width, spacing, inclination, fonts and justification of text.
Change the size, style, units, and accuracy of dimensions.
Change the size and style of symbols, arrows, borders, and patterns.

The edit functions enable you to manipulate diagrams and make quick
corrections in the following manners:

•
•
•
•
•
•
5-4

Cutting drawing objects along an edge
Drawing parallel lines and arcs
Extending drawing objects to an edge
Dividing an object into equal parts
Making sharp and rounded corners
Making chamfered corners


•
•
•
•

Stretching a diagram
Enlarging or reducing a diagram
Rotating a diagram
Mirroring a diagram

Cutting Drawing Objects Along an Edge
CADD allows you to erase drawing objects along a selected edge (this technique is often
called trimming). When you use this function, you are prompted to select the drawing object
that is to be used as the cutting edge and then select the objects that are to be erased
along that edge. (Illustreated with Fig. In CADD PRIMER)

Drawing Parallel Lines and Arcs
CADD allows you to draw parallel lines, arcs or splines using previously drawn
objects as a reference. This technique is often called offsetting. To draw an
offset parallel line, you need to select the drawing object to be used as a
reference and then specify the distance and direction of the offset. A parallel
drawing object is drawn at the specified distance. (Illustreated with Fig. In CADD
PRIMER)

Extending Drawing Objects to an Edge
CADD allows you to extend lines to a selected drawing object. Often you need
to extend lines to construct a drawing and to fix any graphical errors. To extend
lines, you need to select an edge to which the lines should extend and then
select the lines to be extended. (Illustreated with Fig. In CADD PRIMER)

Dividing an Object into Equal Parts
CADD allows you place dividing marks on a drawing object such as a line, arc,
ellipse or spline. To use this command, you need to select an object and specify
how many divisions are required. This function places markers at equal
distances on the drawing object. (Illustreated with Fig. In CADD PRIMER)

Making Sharp and Rounded Corners
CADD allows you to make fine corners of any two lines or arcs. This technique,
often called filleting, is the quickest way to join the missing corners of lines and
arcs. With this function active, to make a corner all you need to do is select the
lines or arcs that have missing corners. CADD automatically extends or
shortens the selected objects to form a corner. You can also specify whether
you want a sharp corner or a rounded corner. (Illustreated with Fig. In CADD
PRIMER)

5-5


Making Chamfered Corners
CADD allows you to make a chamfered corner between two lines. It works quite like the fillet
command. When you enter the chamfer command, you are prompted to select the lines that
are to be chamfered and enter a chamfer distance. The chamfer distance determines the
size of the chamfer. (Illustreated with Fig. In CADD PRIMER)

Stretching Diagrams
CADD allows you to quickly change the size of diagrams by stretching lines,
arcs, splines, etc. This function is very helpful to make quick alterations to
drawings. To use the stretch function, you need to select the drawing objects to
be stretched and specify the distance and direction of stretching. (Illustreated
with Fig. In CADD PRIMER)

Enlarging or Reducing Diagrams
CADD allows you to enlarge or reduce diagrams in a convenient manner. To
enlarge or reduce diagrams, you need to select the objects and enter a scale
factor. The scale factor determines by how much the diagrams are to be
reduced or enlarged. (Illustreated with Fig. In CADD PRIMER)

Rotating the Drawings
CADD allows you to rotate selected drawing objects to a specified angle. To
rotate, you need to select the drawing objects, enter a reference point (or base
point) and the rotation angle. The base point acts as a pivot point around which
the objects are rotated. The rotation angle determines by how much the objects
will be rotated and in which direction. (Illustreated with Fig. In CADD PRIMER)

Mirroring Drawings
CADD allows you to create mirror images of drawings. This capability is very
useful when you want to draw something that is symmetrical on both sides. You
need to draw only one half of the drawing; the rest of the drawing can be
completed using the mirror function. To make a mirror image, you need to
select the objects to be mirrored and indicate a mirror axis. The mirror axis is an
imaginary line along which the diagram is mirrored. (Illustreated with Fig. In
CADD PRIMER)

5-6


The following exercise explains how to draw a plan of a room that we will call an
engineer’s office. The engineer’s office is a room 19 feet, 6 inches long and 13
feet, 6 inches wide, with one chamfered corner and a door in one corner. We
will accurately draw this plan using drawing, editing and view-display functions.
The plan is completed in 16 steps. (Illustreated with Figs. In CADD PRIMER)

AutoCAD MicroStation and Cadkey Terms
This topic lists important terms used in leading CADD programs. Refer to CADD PRIMER for
details.

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5-7

Working With
Layers

6

Contents

6-1


6-2


6-2


6-3

Creating New Layers
Setting a Layer Current
Changing Color and Line Type of Layers
Turning Layers On or Off
Locking and Unlocking Layers

6-3
6-3
6-3
6-3
6-3


6-3


6-3

n
n
n
n
n

6-i

Working With Layers

Note:

Term
Composite
drawing
Layer or
level
Layer color
Layer off
Layer on
Layer line
type
Locking a
layer
Macro

Description
A drawing that contains multiple drawings created with the help of
CADD layers.
A transparent surface created within a drawing.
A color assigned to a layer.
Making the drawing objects on a layer invisible.
Making the drawing objects on a layer visible.
A line type assigned to a layer.
Making the drawing objects on a layer permanent and non-editable.
A recorded set of instructions that can be used to repeat a task.

6-1


Layers are imaginary transparent surfaces that can be created within a CADD
drawing. You can draw on these imaginary surfaces and group drawing objects
on different layers (Fig. 6.1 available in CADD PRIMER). This helps to organize
CADD drawings and makes editing much easier. You can turn the layers on or
off to view or edit specific objects. When you turn a layer off, the objects on that
layer disappear from the screen; when you turn it back on, they are displayed.
Using layers enables you to control the display of specific information on the
screen by turning a combination of layers on or off.
You may create dozens of layers in a drawing to segregate drawing objects. You
may create separate layers to show dimensions, hatch patterns and for any
drawing objects that are different in nature. This provides a great convenience
in editing drawings. When drawings are complex and a number of drawing
objects are overlapping, you can turn off the unwanted layers. This makes it
much easier to select the desired objects for editing. When you are finished
editing, you can turn the layers back on.
Layers are commonly used in professional architecture and engineering
drawings. Architects and engineers often need to coordinate different
engineering services in a plan. They can illustrate different engineering services
on the same drawing using different layers. This helps them understand how
one engineering service relates to another.

Fig. 6.1 illustrates how you can organize an engineer’s office diagram in several
layers. You can place walls and partitions on one layer, furniture and equipment
on another, and so on for text, symbols, and construction lines, etc. You can
also create a separate layer to show the ceiling and lighting plan, floor finish
plan, or any other drawing objects that you want to include in the drawing.
Fig. 6.2 (available in CADD PRIMER) shows how you can display a furniture
plan and a reflected ceiling plan from this multi-layered drawing. When you
need to display the furniture layout as shown in illustration A, you can turn on
the wall and furniture layers, and turn off the rest. When you need to display the
ceiling and lighting plan (Diagram B), you can turn on only the ceiling and the
wall layers. You can turn the relevant text and symbol layers on and off as
required.

Note:
Layers are given specific characteristics that distinguish them from each other.
Each layer has a specific color and line type. Whatever you draw on a layer is
drawn with that color and line type. This color coding helps to identify which
drawing objects are placed on which layer.

6-2


CADD provides a number of tools that allow you to work efficiently with layers.
Most programs use a layer control window that allows you to manage all aspects
of working with layers.
The following are the basic tools for working with layers. These topics are
described in detail in CADD PRIMER.

Creating New Layers
Setting a Layer Current
Changing Color and Line Type of Layers
Turning Layers On or Off
Locking and Unlocking Layers

Layers are not absolutely necessary, however they provide a convenient way to
manage information in CADD drawings. For example, in the engineer’s office
example, without the help of this function you may have to create separate
drawings to show the furniture plan, lighting plan, etc. With the help of layers,
you can create just one composite drawing. The composite drawing can contain
all the plans. It makes it easier to correlate information from one plan to
another.
(See CADD PRIMER for important tips)

This topic lists important terms used in leading CADD programs. Refer to CADD
PRIMER for details.

6-3


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6-4

Introduction to 3D

7

Contents
About this Chapter

7-1


7-2

Why 3D?

7-2


7-2

Oblique Views

7-3

Isometric Views

7-3


7-4


7-4

Isometric Grid
Fixed Cursor Direction
Isometric Circles, Text and Dimensions
2D Drawings to Isometrics Conversion

7-4
7-4
7-4
7-4

n
n
n
n

3D Modeling

7-4


7-5

n
n
n

Spherical Coordinates
Cylindrical Coordinates

n

User-defined Coordinate System

Displaying Views
n
n
n
n
n

View Coordinate Geometry
Object Coordinate Geometry
Displaying Isometric Views
Displaying Plans and Elevations
Displaying Perspective Views

n
n
n

3D Ready-made Shapes
Extruding Objects in the Linear Direction
Extruding Objects in the Circular Direction

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7-5
7-6
7-6
7-6
7-6
7-6
7-7
7-7
7-7
7-7
7-8
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7-8
7-9

0-i

Contents

7-ii

7-9
7-9

Introduction to 3D

Note:

About this Chapter
This chapter introduces you to the general principles of 3D (three-dimensional)
drawing that are commonly used in CADD. It describes how to make use of
simple 2D functions to create a 3D effect, as well as how to create actual 3D
models. You will learn how to measure distances in 3D, how to enter 3D
coordinates and how to draw 3D shapes.
This chapter describes a number of 3D drawing techniques that are commonly
used by CADD professionals. You will learn how to extrude 3D objects from
simple 2D shapes, how to take advantage of 3D ready-made objects and how to
make the views look realistic.
You will also learn how to display 3D views of a model from different angles.
Although the actual working of 3D CADD varies from program to program, the
principles described here can be applied to most programs.

7-1


Term
Isometric
Oblique view
Perspective
3D modeling
3D coordinates
Viewpoint
Linear extrusion
Radial extrusion

Description
A view of an object tilted at 30° on both sides.
A view of an object drawn by taking parallel projections from an
elevation.
A view of an object showing true angles as they would appear from
a specific point.
A CADD capability that allows you to draw objects as physical
objects having length, width and height.
The mode of measurement used to specify the length, width and
height of objects created by 3D modeling.
The point from where a 3D model is viewed.
A 3D technique that allows you to form 2D shapes into 3D shapes
along a linear path.
A 3D technique that allows you to form 2D shapes into 3D shapes
along a circular path.

Why 3D?
3D capabilities allow you to draw pictorial views such as isometrics, oblique
views and perspectives. The views drawn with CADD have a number of
advantages as compared to views drawn on a drawing board. The views drawn
with CADD are very accurate and provide a lot of flexibility in terms of editing
and display. You can rotate a model on the screen just like an actual model, and
display views from different angles.
Designers often use 3D to visualize designs and to make presentations. It helps
them understand how an object will appear from different angles. Using
additional rendering programs can further enhance the drawings.
Although working with 3D CADD programs is quite complex, it is worth the extra
effort to make use of them. Many users never take the time to learn the 3D
capabilities of CADD. This can be a major disadvantage because the full
potential of CADD is never explored.

How do we create 3D views on paper or on a computer screen, which are only
two-dimensional media? Is an isometric or perspective 2D or 3D?
The views that we draw on two-dimensional media are a 2D representation of
3D images. We create isometrics and perspectives on paper by drawing objects
as they would appear from a specific angle and distance. The same concept is
used in CADD to draw pictorial views.

7-2

For more information e-mail mailmaxinfo@aol.com

There are two distinct ways to draw 3D views with CADD: You can draw views
using simple 2D functions or using CADD’s special 3D functions.
The 2D functions allow you to draw views just like on a drawing board. You can
draw a view using lines, arcs, or other 2D objects. This is the quickest method to
draw simple isometric and oblique views. However, a view created this way is
static; just like a view created on a drawing board. If you need to view the object
from a different angle, you will have to draw it again from scratch.
CADD provides special 3D functions that allow you to create 3D drawings that
are true representations of an actual model. These drawings can be viewed
from any angle just like a physical model. That is why 3D CADD drawings are
called 3D models.
The major distinction between a 2D drawing and a 3D model is that a 2D
drawing is defined only with two coordinates (X and Y). A 3D model is defined
with three coordinates (X, Y and Z). The Z-coordinate determines the height of
an object. To make a 3D model, you need to consider all the objects of the
model in 3D space and enter the X, Y and Z coordinates for all drawing objects.
3D modeling is described later in this chapter. Let's begin with simple oblique
and isometric examples.

Oblique Views
Oblique views are the simplest form of the pictorial views that can drawn by
using parallel projection lines from an elevation. There are standards
established to draw oblique views at specific angles. A common standard used
is to draw an oblique view by projecting lines at 45°. To measure depth along a
45° angle, you need to scale it down by 3/4 or 1/2 of the actual distance. For
example, if the actual depth of the object is 1'-0", you measure 9" or 6". The 3/4
scale factor creates an effect as if the object is viewed from a slightly higher
angle than the 1/2 scale factor. (This topic is described in detail with the help of
illustrations in CADD PRIMER).

Isometric Views
Isometric views are more realistic than oblique views. The object appears to be
tilted at a 30° angle on both sides . An isometric is defined by three planes
called isoplanes: top isoplane, right isoplane and left isoplane.
On a drawing board, we use a 30° triangle to draw the three planes of an
isometric. The same principle is applied in CADD with the help of various
functions. The right isoplane is drawn with 30° and 90° angles, the left isoplane
with 150° and 90° angles and the top plane with 30° and 150° angles. All
distances are measured using 1:1 scale (actual size) to show depth, width and
height. You can use simple 2D functions and draw lines at specific angles to
complete an isometric. Polar coordinates are particularly helpful to measure
distances along an angle.

7-3


(This topic is described in detail with the help of illustrations in CADD PRIMER).

The following are some of the important CADD functions that simplify isometric
drawing. These topics are described with the help of illustrations in CADD
PRIMER.

Isometric Grid
Fixed Cursor Direction
Isometric Circles, Text and Dimensions
2D Drawings to Isometrics Conversion

3D Modeling
CADD’s 3D modeling capabilities allow you to create 3D images that are as
realistic as the actual objects. These images are called 3D models because, just
like a physical model, they can be rotated on the screen. You can display views
from a 3D model, such as isometrics or perspectives, from any angle with a few
simple steps.
3D modeling is usually a separate CADD module that has its own set of
functions. Some manufacturers market 2D programs and 3D programs as
separate packages while others combine them into a single program.
The 3D models fall into the following categories:

•
•
•

Wire-frame models
Surface models
Solid models

Note: The above topics are described in detail with the help of illustrations in
CADD PRIMER.

7-4


3D coordinates are measured with the help of three axes: X, Y, and Z. The axes
meet at a point in the shape of a tripod. This point is called the origin point,
which is the 0,0,0 location of all coordinates. All distances can be measured
using this point as a reference. (Illustrated with Fig. In CADD PRIMER)
The three axes form three imaginary planes: XY plane, XZ plane and YZ plane.
The XY plane is the horizontal plane and the XZ and YZ are the two vertical
planes. When you need to draw something horizontal, such as the plan of a
building, you draw it in the XY plane using X and Y coordinates. This generates
a plan view. When you need to draw something vertical, such as an elevation of
a building, you draw it using the XZ or YZ planes.
Example:

To draw a line in 3D, enter two end points defined with X, Y and Z
coordinates. If you need to draw the line lying flat on the ground (XY
plane), the Z coordinate for both the end points of the line is zero. If
you want to draw the same line at 10’-0” above the XY plane, enter
the Z-coordinate for both the end points as 10’-0”.

The 3D coordinates can be entered using the following formats:

•
•
•

Spherical coordinates
Cylindrical coordinates

Cartesian coordinates are based on a rectangular system of measurement. In
Chapter 2 “CADD Basics”, we discussed how Cartesian coordinates are used in
2D drawings. The same principle is applied to enter 3D coordinates with the
exception that you need to enter an additional Z coordinate. Positive Zcoordinate values are used when you need to measure distances above the XY
plane; negative values are used for the distances below the XY plane.
(Illustrated with Fig. In CADD PRIMER)
Coordinate values are entered separated by commas (X,Y,Z). The coordinates
can be measured from the origin point (absolute coordinates) or from the last
reference location of the cursor (relative coordinates).

Spherical Coordinates
Spherical coordinates are based on the longitude and latitude system of
measurement. Consider the origin point of the coordinate system at the center
of the earth or a transparent globe. Then consider a horizontal plane (XY plane)
passing through the center of the globe. To locate a point in 3D, first locate a
point in the XY plane by specifying a radius and an angle (polar coordinates). To
specify the height, enter an angle up or down from the XY plane (latitude).
(Illustrated with Fig. In CADD PRIMER)

7-5


Note:
Spherical coordinates are not very efficient for drawing purposes. They are
commonly used to view a model from different angles.

Cylindrical Coordinates
Cylindrical coordinates are commonly used to draw cylindrical shapes. They are
based on a cylindrical system of measurement. Consider a cylinder placed
vertically and the origin point at the center of the cylinder. Cylindrical
coordinates are quite similar to spherical coordinates, the difference being that
the Z-coordinate is specified by height and not angle. (Illustrated with Fig. In
CADD PRIMER)
To locate a point with the cylindrical coordinates, first you need to locate it in the
XY plane just like polar coordinates. Then indicate an exact height at that point.

(This exercise is described with the help of illustrations in CADD PRIMER).

User-defined Coordinate System
We discussed in Chapter 2, “CADD Basics”, how a user-defined coordinate
system can help to work with odd-shaped diagrams. Here is an example of
using it in 3D. (This topic is described in detail with the help of illustrations in
CADD PRIMER).

Displaying Views
You can rotate a 3D model on the screen and display different views by
specifying an exact viewpoint. The viewpoint represents the position of the
camera from where a picture of the view is to be taken. You can define a
viewpoint with the help of any of the coordinate methods discussed earlier.
There are two main protocols used to display views:
•
•

View coordinate geometry
Object coordinate geometry

View Coordinate Geometry
View coordinate geometry assumes that the camera (viewpoint) remains
stationary and the 3D model is rotated to display a desired view. The model can
be rotated around the X, Y, or Z axis. You need to specify around which axis the

7-6


rotation will take place and by how much. When you rotate the model around
the Z-axis, the model rotates in the XY plane; when you rotate it around the Yaxis, the rotation takes place in the XZ plane. (Illustrated with Fig. In CADD
PRIMER)

Object Coordinate Geometry
Object coordinate geometry assumes that the model remains stationary and the
camera (viewpoint) is moved to a display a desired view. You can use any of
the coordinate methods to specify an exact viewpoint. Spherical coordinates are
particularly helpful to indicate a viewpoint. (Illustrated with Fig. In CADD
PRIMER)
Comparison: View coordinate geometry can be compared to holding a small
model in your hand and rotating it on its sides to get a desired
view. Object coordinate geometry can be compared to viewing a
building from the sky. The building remains stationary, while the
camera is moved to get a desired view.

Note: Most CADD programs provide both view coordinate geometry and
object coordinate geometry options to display views. Depending on how
you want to view a model, you can use either method.

Displaying Isometric Views
To display an isometric, you need to specify the direction from which the view is
to be taken. The most appropriate method to indicate direction is with the help
of spherical coordinates. You need to specify two angles: an angle in the XY
plane (longitude) and an angle from the XY plane (latitude). The longitude
determines the orientation of the model in the XY plane and the latitude
determines the height of the viewpoint. (This topic is described in detail with the
help of illustrations in CADD PRIMER).

Displaying Plans and Elevations
You can display standard 2D views such as plans and elevations by specifying
the direction of the view. To display a plan view, you need to view the model
from the top, that is, enter the angle from the XY plane (latitude) as 90°. To
display an elevation, you need to view the model parallel to the XY plane, that
is, enter the angle from the XY plane (latitude) as 0°. You can view an elevation
from any angle by specifying an exact angle in the XY plane. (This topic is
described in detail with the help of illustrations in CADD PRIMER).

Displaying Perspective Views
CADD allows you to display perspective views from any angle of the model. You
can display a true perspective by specifying an exact distance between the
viewpoint and the model. (Specifying a distance is not necessary to display

7-7


parallel projection views such as plans, elevations and isometrics.) When you
specify an exact distance, it causes the lines of the view to converge and
display a true perspective (See Fig.). The closer the viewpoint, the greater the
conversion takes place.
CADD programs use one of several different methods to display perspective
views. A common method is to establish a line of sight between the viewpoint
(camera) and the model (target). You can specify any distance along this line of
sight to display an appropriate perspective view. (This topic is described in
detail with the help of illustrations in CADD PRIMER).

The common 3D drawing-aid functions of CADD are described as follows:
•
•
•
•

3D ready-made shapes
Linear extrusion
Radial extrusion
Shading and rendering

3D Ready-made Shapes
CADD allows you to draw a number of 3D ready-made shapes in a few simple
steps. To draw a cube, you don't need to draw all the lines or 3D faces for each
of its sides. You can instantly draw a cube by specifying its dimensions.
Similarly, you can draw a number of commonly used geometrical shapes just by
specifying their shape and size. (This topic is described in detail with the help of
illustrations in CADD PRIMER).

Important Tip:
Specialized engineering programs provide a number of additional 3D shapes to
facilitate a 3D drawing. The 3D ready-made shapes can help build the skeleton
of a model.

Extruding Objects in the Linear Direction
CADD allows you to extrude 3D shapes from 2D profiles. You can extrude a
square to form a cube, a circle to form a cylinder, or a triangle to form a prism.
When you use the linear extrusion function, you are prompted to select the
objects to be extruded and specify the direction of extrusion (axis of extrusion).
You can select any profile made of lines, arcs, polylines, or other objects and
extrude it in any direction by specifying the axis of extrusion. (This topic is

7-8


Extruding Objects in the Circular Direction
CADD allows you to extrude drawing objects along a circular path (called radial
extrusion). For example, you can draw a section of a cylinder and extrude it to
form the complete cylinder. To perform a radial extrusion, you are prompted to
select the objects to be extruded, indicate an axis of revolution and an angle of
extrusion. The axis of revolution acts as pivot point of the revolution and the
angle of extrusion determines how much revolution will take place. (This topic is

There are a number of shading and rendering programs available that can be
used to make 3D drawings very realistic. These programs allow you to create
colors, shades and shadows exactly as they would appear in a picture. These
programs are quite large and complex and require powerful computer hardware.
With the help of rendering programs, you can specify a number of shading and
rendering parameters and create a 3D scene. You can assign colors and
textures to different surfaces of a model. You can specify light sources in a
scene and specify what kind of light is used and how it is directed. You can
create a special setting for the model, such as a landscape or interior.
This topic is described in detail in CADD PRIMER.

This topic lists important terms used in leading CADD programs. Refer to CADD
PRIMER for details.

$10
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7-9


address.
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7-10

Printing and
Plotting

8

Contents
About this Chapter

8-1


8-1


8-2

Selecting a Scale for Drawings
Composing a Drawing Layout
Selecting Text and Dimension Heights
Choosing Pens, Colors and Line weights

8-2
8-2
8-3
8-3

Steps to Plotting

8-3


8-4

Pen Plotters
Ink-Jet Printers/Plotters
Laser Printers
Electrostatic Printers/Plotters


8-4
8-4
8-4
8-4
8-4

8-i


Note:

About this Chapter
This chapter introduces you to the printing and plotting process. It describes how
the drawings are printed using a printer or a plotter. It looks at a number of
issues associated with printing such as how to apply a scale to CADD drawings,
how to select a sheet size and how big or small diagrams can be drawn, how to
compose a drawing layout for plotting and what height text should be used
based on a scale.
This chapter describes basic steps for plotting and how colors and line-weights
are created in the drawings.
It also includes a discussion on common printing and plotting machines. You will
learn about pen plotters, ink-jet printers/plotters, laser printers and electrostatic
printers/plotters.

Term
Configure
Dpi
Line weight
Plot
Plotting
origin

Description
A process by which a program, such as CADD, is made to recognize and work
with a hardware component, such as a plotter.
Dots per inch; used to measure the accuracy of printing.
Thickness of lines and other drawing objects.
To print a drawing with a plotter.
An imaginary point on the screen that is used to align screen image with the
paper in the plotter.

8-1


Term
Plotting scale
Plotting scale
factor

Description
To proportionally reduce or enlarge diagrams for plotting.
A degree to which drawings are proportionally reduced or enlarged.

CADD drawings are printed using a printer or a plotter. The process of printing is
as simple as selecting the print or plot function from the menu. This action
sends data from the computer to a printer or plotter, which produces the final
drawing. The drawings are neat, clean and, depending on the quality of the
printer, highly accurate.
You can specify a number of parameters to control the size and the quality of a
plot. You can plot a drawing to any size by applying an appropriate scale factor.
You can specify line thickness and colors for different drawing objects. You can
make a number of other adjustments as well, including rotating a plot, printing
only selected areas of a drawing, or using specific fonts for text and dimensions.
The following are the important considerations for plotting:

•
•
•
•

Selecting a scale for drawings
Composing a drawing layout
Selecting text and dimension heights
Choosing pens colors and line weights

Selecting a Scale for Drawings
When working on a drawing board, you use a specific scale to draw diagrams.
For example, when you need to draw a plan of a building or a township, you
reduce the size of the diagrams to 1/100 or 1/1000 of its actual size, that is, you
use a 1:100 or 1:1000 scale. When you need to draw a small machine part, you
draw it many times larger than its actual size. CADD uses the same principle to
scale the drawings; however, a different approach is taken.
For details on this topic refer to CADD PRIMER.

Composing a Drawing Layout
CADD provides a number of special functions to compose a drawing layout. You
can arrange diagrams on a sheet as you like and apply any scale factor.
Different programs use different protocols to accomplish this task.

8-2


The following table shows some of the standard sheet sizes (in inches):

ANSI
Mark
A
B
C
D
E

Size
8.5x11
11x17
17x22
22x34
34x44

ISO
Mark
A4
A3
A2
A1
A0

Size
8.3x11.7
11.7x16.5
16.5x23.4
23.4x33.1
33.1x46.8

Architectural
Mark
A
B
C
D
E

Size
9x12
12x18
18x24
24x36
36x48


Selecting Text and Dimension Heights
As diagrams are enlarged or reduced by applying a scale factor, the size of text,
dimensions, patterns and symbols is also changed. When you place different
scale diagrams on the same sheet, you may get different sized text for each
diagram. This is generally not acceptable for professional drawings. It is better
to have consistently sized text on the drawings regardless of their scale.

Choosing Pens, Colors and Line weights
CADD allows you to work with a variety of colors and line weights depending upon the
plotter. In most CADD programs, the colors you use on-screen are configured with a specific
line weight in the plotter. For example, the objects drawn with red color on-screen may be
printed with .5mm line weight; the objects drawn with blue color may be printed with .2mm
line weight. These are called pen assignments.


Steps to Plotting
The following are the basic steps to plotting.

Step
1
2
3
4

Action
Set up the plotter according to the manufacturers specifications and configure it
with your CADD program.
Place paper in the plotter and run a self test to ensure that the
paper path is clear and the pens or cartridges are in good working condition.
Display the drawing to be plotted on the screen and choose the Plot function.
Respond to the specific prompts of your CADD program. In general, a CADD
program will require the following information to plot the drawing:

Plotting area:
You can plot a part of the drawing or the entire drawing. You will be able to indicate
the plotting area by indicating a window (an imaginary rectangle formed by two

8-3


diagonal points) or by selecting a specific view for plotting.

Plotting scale factor:
Enter a scale factor based on how big or small you want to print the drawing and
the sheet size used. (See topic Selecting a Scale for Drawings.)

Plotting origin:
The plotting origin is a point that allows you to align the drawing shown on the
screen with the paper in the plotter (see Fig. 8.2). You can place the diagrams on
the paper anywhere by entering the exact coordinates of the plotting origin.

Important Tip:
Its always better to do a test plot of a small area of the drawing before sending
all the drawings to plotter or printer.

Printers and plotters are used to print CADD drawings. The drawings are
generally printed at about 300-600 dpi (dots per inch) accuracy, which is
considered quite high precision for engineering drawings. There are machines
available that can print at 1200 dpi or higher accuracy as well.
The following are some examples of printers and plotters. Refer to CADD
PRIMER for details on these topics.

Pen Plotters
Ink-Jet Printers/Plotters
Laser Printers
Electrostatic Printers/Plotters

Refer to CADD PRIMER for important print function terms used in leading CADD
programs.

8-4


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8-5

Maximizing
CADD

9

Contents
About this Chapter

9-1


9-2


9-2

Developing CADD Symbol Libraries
Using Macros
CADD Drawing Automation
Customizing CADD
Using CADD Database

Calculation Programs
Intelligent CAD
Knowledge-based CAD Systems

9-3
9-3
9-3
9-3
9-3
9-4
9-4
9-5
9-5

Integrated Systems

9-5


9-5


9-6

9-i

Maximizing CADD

Note:
understanding of CADD refer to CADD PRIMER. This complete book is available for
download for $9.95 at http://www.caddprimer.com or you can order printed copies through the
publisher listed at the end of this chapter.

About this Chapter
So far, we have concentrated on CADD’s drawing capabilities. But CADD is able
to do much more than just drawing. It can help you design, perform analyses,
and accomplish many automated tasks. There are a number of applications for
CADD in architectural design, engineering calculations, product design, etc.
This chapter contains two main topics:
•
•


Streamlining CADD Drawing Environment describes how to maximize CADD’s
drawing efficiency using symbol libraries, macros and customizing features. It
also describes how CADD can be used to prepare project reports and cost
estimates using database functions.
The Design Application of CADD describes how CADD can help you in design
work. It outlines some categories of artificial intelligence programs associated
with CADD and describes the concepts behind them.
Note: The objective of this topic is to give an overview of research and
development taking place in the field of CADD. Although, artificial
intelligence is out of the scope of this book, it introduces you to some of
techniques and terms used in the artificial intelligence CAD industry.

9-1

Maximizing CADD

Term

Description

Artificial intelligence
(AI)
Attribute
CAFM
Database
Design automation
Download
Drawing automation
DWF
FEM
FTP
Fuzzy-logic

Integrated system
Intelligent CAD
Knowledge-based
system
Lisp
Macro
Parametric
modeling
Spreadsheet
SVF
Upload

A computer capability that enables the computer to think and make
decisions.
A description of a drawing object that is directly linked with the
drawing.
An acronym for Computer Aided Facility Management.
A collection of data that can be extracted in several formats.
A term associated with making the design procedures automatic.
A procedure for transferring electronic files from a web site to a
remote computer.
A term associated with making the drawing process automatic.
An acronym for Finite Element Method. It is programming technique
commonly used for structural design programs.
An acronym for File Transfer Protocol. It is a procedure used to
upload and download files on the Internet.
A programming technique used in artificial intelligence programs that
can draw conclusions even if the statements are not completely true
or false.
A group of programs that can work together as one package.
A computer program with artificial intelligence and CADD
capabilities.
A category of artificial intelligence programs that makes use of
information gathered from previous projects.
A programming language used in AutoCAD.
A set of commands recorded in a file and played back to perform a
task.
A capability of CADD that links calculations with the geometry of
diagrams.
An electronic chart that contains information in rows and columns.
A procedure for transferring electronic files to a web site from a
remote computer.

When you start working with a new CADD program, it can be very slow to work
with in the beginning. You can get efficient with CADD only when you use
shortcut methods and special editing techniques, develop symbol libraries and
implement prototype drawing standards.
The following are some of the essentials for maximizing CADD:

•
•
•
9-2

Developing CADD symbol libraries
Using macros
Add-on CADD software


•
•

Customizing CADD
Using CADD database

Developing CADD Symbol Libraries
There are many symbols used in drawings that you may need to draw again and
again. You don't need to draw these symbols every time you need them. You
can draw them once and store them in special directories. These directories act
as symbol libraries that can be readily accessed whenever you need a symbol.
Refer to CADD PRIMER for details on this topic.

Using Macros
A macro is a set of instructions recorded in a file that can be played back to
perform a task. A sequence of instructions can be stored as a macro, which can
be run at any time. As a result, using a macro can reduce a complex and
lengthy process down to a single click of a mouse button or key.

CADD Drawing Automation
It is the dream of a CADD user to have CADD do as much work as possible.
Can CADD be used to draw elevations from plans? Can it dimension the
drawing automatically? Can it draw a 3D view from plans and elevations? With
the help of advanced programming, it is possible to accomplish all of these
tasks.

Customizing CADD
Customizing CADD plays a major role in achieving drawing efficiency. Most
CADD programs allow you to customize them.

Using CADD Database
CADD allows you to develop a database that is linked with the diagrams in the
drawing. You can add descriptions of drawing objects (attributes) in the
database and link them to diagrams. The attributes can be used to describe
many characteristics of diagrams, such as size, color, area and price. If you
draw a symbol of a chair, it is just lines and arcs in computer memory; the
computer does not know what it is. With the help of special CADD functions,
you can describe all the attributes associated with it.

9-3

Maximizing CADD


Although CAD is an acronym for computer-aided design and CADD for
computer-aided design and drafting most programs do not offer any design
capabilities. They are just drafting programs, but manufacturers call them CAD
or CADD anyway. You may be able to work out designs using the drafting
capabilities of CADD, but that is not real computer-aided design. A CADD
program can be truly called a design program only when it has the ability to
solve problems and perform analyses.
Design is a vast subject and has different applications for different
professionals. It has a specific meaning to an architect, a structural engineer, a
civil engineer or a mechanical engineer. An architect may use CADD to design
a building part, a structural engineer may use it for a design calculation and a
civil engineer may use it for certain site design analysis.
The design applications of CADD are still a subject of research. Many academic
institutes offer postgraduate courses dedicated to research and development of
CADD design software. Some design programs have been developed for
engineering applications, but generally they need to be customized.
Design programs are based on a number of principles and vary significantly in
their approach. Some are mainly based on calculations, some involve
comparison and logic in the program, while others involve the use of a database
or another form of artificial intelligence. The following are some examples of
design programs:
•
•
•

Calculation programs
Intelligent CAD
Knowledge-based CAD systems

Calculation Programs
Calculation programs are extremely effective in solving complex mathematical
problems. Specialized engineering CADD programs are designed to compute
scientific, trigonometric, logarithmic and exponential functions. They can be
used to perform many inter-connected calculations. If one variable in the
calculation is changed, the program automatically adjusts the rest of the
calculations. For example, a structural engineer working with frame structures
does not have to calculate all the members each time a new span or load is
added to the structure. The computer program understands that everything else
is constant except the load and the span and can give the end results within
seconds.

9-4


Intelligent CAD
Intelligent CAD programs are based on logic and comparison, and have a
number of applications in product design, mechanical design, space planning,
etc. These programs are not based purely on mathematics as the calculation
programs. Besides mathematics, they analyze forms, shapes, arrangement of
objects, patterns, colors, etc. They can draw conclusions even if the resulting
statements are not completely true or false (a technique known as Fuzzy-logic).

Knowledge-based CAD Systems
Knowledge-based CAD systems (also known as expert systems), make use of
information gathered from previous projects (or parameters defined by the
programmer) and use it for new design proposals. The knowledge-based
systems enable large corporations to constantly improve their design and
manufacturing process. Let's say an engineering firm specializes in automobile
design. They may have designed dozens of automobiles and have encountered
hundreds of design problems associated with them. To design a new
automobile, they don't need to address all the issues again. They can use the
information gathered in the knowledge-based system to find quick solutions.

Integrated Systems
Integrated systems are a group of systems and software that can work in a
network environment and share information. This approach is commonly
adopted in large corporations that need hundreds of computers networked. The
integrated systems are designed to include different application programs in one
package. The programs are able to work as independent programs as well as
share information.

Internet is changing the way professionals collaborate CADD projects. Professionals can work
as team and share CADD drawings with others thousands of miles away. The drawings can
be sent using the E-mail and are delivered within minutes. Another method of distributing
drawings is FTP. Using the FTP method, you can upload the CADD drawing files to specific
server or web site. Any one with access to that server or web site can download the drawings.
The E-mail and FTP methods are ideal for distributing drawings, however they do not
provide real-time interaction between the team members. There are a number of project
collaboration software available that allow you to instantly publish and share your drawings
on the web.


9-5

Maximizing CADD

This topic lists research and development resrources associated with the CADD
artificial intelligence industry. Refer to CADD PRIMER for details.

Important Tip:
CADD programs are constantly being updated. There are new features added
every time a new release comes out. However, the future of the CADD industry
lies in the drawing automation and artificial intelligence programs. The
advancement in this field has just begun. There are only a few such programs
currently available; it is a wide-open field for anyone to explore. We will
certainly see more advancement in this field over the next decade.

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9-6

CADD Industry
Resources

10

About this Chapter

10-2

CADD Industry Terms

10-2


10-3


10-4

Architectural Engineering Construction (AEC)
General Purpose
Visualization and Rendering
Facility Management CADD
Mechanical CADD
Solid Modeling
CAD/CAM/CAE

Organizations associated with CADD
CADD magazines and journals
CADD Directories and Gateways
Important CADD Resources
Important CADD Links
CADD vendors

10-4
10-4
10-5
10-5
10-5
10-5
10-6
10-6
10-6
10-7
10-7
10-8
10-8
10-8

10-1


Note:
understanding of CADD refer to CADD PRIMER. This complete book is available for download
for $9.95 at http://www.caddprimer.com or you can order printed copies through the publisher
listed at the end of this chapter.

About this Chapter
Implementing CADD is a big expense. It is worth the extra effort to take the
time you need to select the right CADD program. With so many programs
available, it is likely to get confusing. Each CADD vendor claims his or her
product to be superior. The best answer may come if you review each
program in light of your requirements.
This chapter describes the general criteria for selecting a CADD program and
lists a number of leading CADD products and resources. Note that most
companies offer more than one CADD program and may be able to customize
the program with add-on programs.

CADD Industry Terms
Term
AEC
ANSI
Boolean modeling
CAE
CAFM
CAM
CGM
DXF
EDM
GIS
IGES
ISO
MCAD
Parametric
modeling
PDM
Solid modeling

10-2

Description
Architecture, engineering and construction application.
American National Standards Institute
A 3D modeling technique that allows to add or subtract 3D shapes
from one model to another.
Computer aided engineering.
Computer aided facility management
Computer aided manufacturing
Computer graphics metafile
Data exchange format - A standard format commonly used to
exchange drawings from one application to another
Engineering document management
Geographic Information System
International Graphics Exchange Specification - A standard format
used to exchange drawing data between one application and another
International Standards Organization
Mechanical CAD
An ability of CADD to link geometry with the calculations.
Product Data Management
3D modeling that assumes the 3D objects to be solids having weight
properties.


The following criteria may help you make a CADD program selection:

•
•

•
•

•
•
•

Is CADD intended for personal use or professional? A low-end product
may be accepted for personal use, but for professional use, you may
want to consider a high-end product.
Select a program compatible with the programs used by your clients and
consultants. It makes sharing drawings much easier. Although you will
often hear from the CADD vendors that their programs are 100%
compatible with other programs, it may not be the case. Ask for a trial
version of the program and confirm it.
Review how many customization features a CADD program offers.
Customization plays a major role in making CADD more productive.
Decide whether you need to buy a brand name product or any workable
CADD program. Both may provide the same capabilities, but a brand
name may cost twice as much. Selecting a brand name program may
give you certain advantages such as finding add-on programs and
experienced users.
Find out if the dealer offers technical support. In the beginning you may
have a lot of questions about the program. Without technical support, you
may have to pay hourly charges to a consultant.
Ask if the dealer offers free or low-cost updates of the program. Most
CADD programs get revised every year. You may have to pay double in
four or five years to get all the updates.
New technology advancements are taking place everyday. CADD
programs are getting highly specialized to meet the needs of specific
professionals. With some research you may be able to find exactly what
you need and you may not have to spend a bundle.

10-3


Today’s CADD market has become highly specialized. Most CADD programs as
designed to meet the needs of a specific industry. CADD companies offer different
varieties of their basic program to target a specific market.
The CADD programs may be divided into the following categories:

•
•
•
•
•
•
•

General-purpose
Mechanical CAD
Solid modeling
Visualization and rendering
Facility management
CAD/CAM/CAE

Refer to CADD PRIMER for contact information and applications.

Product (s)

Contact Information

Application

Allplan, MiniCAD
ARCHICAD
ARCHITRON
ArchT
ARRIS
AutoCAD, rchitectural
Desktop, AutoCAD LT
CHIEF ARCHITECT
MicroStation
DATACAD
SoftCAD, SoftCAD.3D,
ArchiTECH PC

General Purpose

Product (s)
CADVANCE
DENEBACAD
DesignCAD
DYNACADD
EasyCAD, FastCAD
FELIXCAD
POWERCAD

10-4

Contact Information

Application


Smart Sketch
VDRAFT
VISIO TECHNICAL

Visualization and Rendering

Product (s)

Contact Information

Application

AccuRender
3D Studio MAX,
3D Studio VIZ,
LIGHTSCAPE
Art*lantis
FormZ
Virtus

Facility Management CADD

Product (s)

Contact Information

Application

APERTURE
ARCHIBUS
DRAWBASE

Mechanical CADD

Product (s)

Contact Information

Application

CADKEY
CADMAX
AutoCAD, Mechanical
Desktop
VELLUM

Solid Modeling

Product (s)

Contact Information

Application

Helix Design System
IronCAD
SOLIDWORKS

10-5


CAD/CAM/CAE

Product (s)

Contact Information

Application

CADRA
CATIA-CADAM
I-DEAS
Pro/Engineer, CADDS,
MEDUSA
Unigraphics,Solid Edge

CADD resources available on the Internet are vast. There are more than 100,000 web sites
established for CADD-related products and services. If you search the web for the words CAD or
CADD, it will list thousands of sites within seconds. You can spend a lifetime researching CADD
using the Internet. The following are some important resources on the Internet:
Note: You can access the following sites through a web site dedicated to this book at
http://www.caddprimer.com

Organizations associated with CADD
Description

Internet address

Association for Computer Aided Design in
Architecture (ACADIA)
Facility Information Council (FIC) of
National Institute of Building Sciences
(NIBS):
An organization involved in developing U.S.
national CAD standards.
CAD Society

http://www.acadia.org/

American Design and Drafting Association
(ADDA)
American Society of Mechanical Engineers
(ASME)

http://www.adda.org/

Institute of Electrical & Electronics
Engineers (IEEE)

http://gopher.ieee.org/
(Search for word CAD)

American Institute of Architects (AIA)

http://www.aiaonline.com/
http://www.caadria.org/

Computer Aided Architectural Design
Research In Asia (CAADRIA)
Education in Computer Aided Architectural
Design in Europe (ECAADE)

10-6

http://nationalcadstandard.org/
http://www.nibs.org/

http://www.cadsociety.com/

http://www.asme.org/

http://www.ecaade.org/


CADD/GIS Technology Center: A multiagency vehicle to coordinate CADD/GIS
standards used by US Department of
Defense and other government agencies.

http://tsc.wes.army.mil/

CADD magazines and journals
Description
CADENCE: A leading CADD magazine
focusing on the CADD industry.
CADSYSTEMS: A leading CADD magazine
focusing on the CAAD industry. Available
for free in Canada.
CADALYST: A popular magazine focusing
on AutoCAD.
An electronic CADD magazine (e-zine)
focusing on the CADD industry news. You
can subscribe this weekly e-zine free of
charge.
Joint CAD Journal: Engineering magazine
from Russia
TCAD Journal: The Journal of Technology,
Computer Aided Design.
CAD/CAM Publishing: books, magazines,
industry links
CAD User Online: Australian/ Neuziland
CAD magazine

Internet address
http://www.cadence-mag.com/
http://www.cadsystems.com/

http://www.cadonline.com
http://www.upfrontezine.com/

http://sungraph.jinr.dubna.su/jcj/
http://www.ieee.org/journal/tcad/
http://www.cadcamnet.com/
http://www.caduser.com.au/

CADD Directories and Gateways
Description
3zone: A comprehensive database of
CADD companies, publications and
resources
CAD baseline URL database: Allows you to
search products in a specific category
CAD Forum: CADD news, employment,
companies, usergroups, dictionary
CAD on the Web: A database of CADD
products and services
CAD open directory: Maintains a list of
CADD products in different categories
Product Information Retrieval System
(PIRS) for construction & design
professionals
TenLinks: A comprehensive directory of
CADD products

Internet address
http://www.3zone.com/

http://www.basline.com/basline/cadURLs.htm/
http://www.cad-forum.com
http://www.cadontheweb.com/
http://dmoz.org/computers/cad/
http://www.insa.com/

http://www.tenlinks.com/

10-7


Important CADD Resources
Description
AEC Info. Center: architecture, engineering,
building construction links
Architectural CADD: Ratings and reviews
CAD Depot: CADD software resource
CAD Info net: CADD news, reviews and
links
CAD Source International: Australia
Daratech, Inc.: Ranking of CADD software
The CAD Place: Comprehensive lists of
CADD products and services

Internet address
http://www.aecinfo.com/
http://www.architecturalcadd.com/
http://www.caddepot.com/
http://www.cadinfo.net/
http://www.cadsource.com.au/
http://www.daratech.com/
http://www.cadplace.cjb.net/

Important CADD Links
Description

Internet address

CADD rating guide
Technical drawing/drafting resources on the
Internet
Technical drawing/drafting resources on the
Internet
PC and CAD encyclopedia on the web and
links
CAD-CAM & graphics sites around the
world
CAD home page: U.S. Department of
Energy

http://www.cadratingguide.com/
http://www.gmi.edu/official/acad/mecheng/drafting.htm
http://www.gmi.edu/official/acad/mecheng/drafting.htm
http://www.pcwebopaedia.com/CAD_CAM.htm
http://www.flash.net/~cdhb/Cadlinks2.htm
http://www-cad.fnal.gov/

CADD vendors
Description
Proven Solutions, Inc.: Links to over 480
hardware and software manufacturers.
CAD Studio on-line: CADD links
CADD links and symbol libraries
Design Technology Warehouse
CAD information sources and
manufacturers
The CAD Shack: CADD industry links
CAD WIRE: CAD/CAM training and support

10-8

Internet address
http://www.proven-solutions.com/
http://www.cadstudio.cz/
http://www.cadeasy.com/
http://wwwcad.eecs.berkeley.edu/Software/software.html
http://www.compinfo.co.uk/tpcad.htm
http://www.cadshack.com/
http://www.cadwire.com/


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