3 d video streaming for virtual exploration of planet surface

IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 03 Issue: 05 | May-2014, Available @ http://www.ijret.org 645
3D VIDEO STREAMING FOR VIRTUAL EXPLORATION OF PLANET
SURFACE
Himanshu S Mazumdar1
, Divya J Nimavat2
, Marichi Patel3
1
Head, Research and Development Center, Dharmsinh Desai University, Nadiad, Gujarat, India
2
Student, Department of Information Technology, Dharmsinh Desai University, Nadiad, Gujarat, India
3
Research Scholar, Research and Development Center, Dharmsinh Desai University, Nadiad, Gujarat, India
Abstract
Human perception is far superior then vision analysis by computer. The visual objects like distant planet surface (terrain) are not
accessible to observer. This could be presented to human analyst in most natural representation like virtual 3D anaglyph for browsing
and visual analysis. The paper represents development of a stereoscopic 3D viewer application for planetary surface. For 3D stereo
visualization of virtual 3D geo-based data model, Anaglyph Method is most cost-effective as compared to other method like paired
epipolar images, Multi-view display, integral imaging display. 3D anaglyph scene generated using Digital Elevation Map (DEM) and
satellite imagery data sets for this study. The objective is to use the planetary optical remote sensing data which is available in the
public domain database to create an application to study the formation of specific planet surface. Implementation for 3D animated
anaglyph DirectX library is used. 3D Terrain generation and rendering is vastly used in computer games, but here we use 3D terrain
generation for scientific use like, studies of relative and absolute surface (age), Analysis of Planetary Surface and its formation,
Analysis of specific crater for scientific purpose, for safe landing site identification, Mineralogical mapping of planet, Ejecta
mapping.
Keywords: Virtual Reality, Stereoscopy, DEM, 3D anaglyph, anaglyph map, DirectX
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1. INTRODUCTION
The use of 3D visualization technique in planetary exploration
in order is to display planet data in such a way that it is useful
for analyze and browse the important parameter of the planet.
The 3D visualization can be developed using either DirectX
Graphics or OpenGL Graphics which provide a light buffer to
shield the developer from immediate effects of technical
changes.
Both provide developers with direct access to any installed
high-performance PC hardware but DirectX, which is most
frequently updated (with eight versions having been released
since its introduction in 1995) and offers a wider range of
functions than OpenGL, is possibly the more widely used in
the games environment.
DirectX is a fast device-independent means of accessing any
multimedia hardware in the Windows operating system
environment. Its each component APIs each control a set of
low-level functions, that access the hardware or enable
software emulation of a feature not provided by the hardware,
and include support for 3D graphics acceleration as well as
control over numerous input devices such as keyboards, mice
and joysticks. DirectX therefore have the ability to utilize
more efficiently multimedia and graphics accelerator features
such as advanced sound cards and 3D acceleration cards.
DirectX architecture was therefore chosen to support the
development undertaken during this project. However,
DirectX‟s software layer that allows communication with any
type of graphics card is unnecessarily complex for the number
of features required in this design and therefore a simpler form
of access to Direct3D/DirectX Graphics has been written into
the program.
The implementation is done using Direct3D. OpenGL works
on any OS where an OpenGL driver has been written. Even
though Direct3D is not cross-platform graphics API but it has
advantage over OpenGL. OpenGL is written to a specification
maintained by the OpenGL Architecture Review Board. That
means the API is slow to adopt new features on graphics
cards, and not all graphical effects are supported on all cards.
Some game consoles also support the use of Direct3D, which
is released more often than OpenGL and contains a specific
set of functionality which driver developers must include.
In the present project, it is proposed to work on Martian
surface map where satellite-derived high resolution DEMs,
generated by optical stereoscopy. This Martian database is
downloaded from public domain database which is taken from
Mars Global Surveyor (MGS) mission and MOLA data.

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1.1 Digital Elevation Model (DEM)
A DEM can be symbolized by a raster (a grid of squares) or by
a triangular irregular network. Frequently DEMs are
constructed using remote sensing techniques, but, they may
also be made from land survey. Geographic Information
Systems use DEMs quite often and are the most regularly used
for digitally creating relief maps.
There are a lots of different standards, how to store elevation
data. The used formats are Digital Elevation Models that use
two-dimensional arrays of height values. These DEMs also
contain a latitude/longitude position and data resolution (10m,
1km ...). Satellite elevation data are most often stored as
USGS-DEM files (.dem). In games grayscale images (height
maps) are a common solution to specify terrain data.
1.2 Anaglyph Method
Anaglyph 3D is the name given to the stereoscopic 3D effect
achieved by means of encoding each eye's image using filters
of different (usually chromatically opposite) colors, typically
red and cyan.
Anaglyph is a type of stereo 3D image created from two
photographs taken approximately 2.5 inches apart, the center
distance typically between human eyes. The Red color field of
the left photo is combined with that of the right photo in such
a way as to create the illusion of depth. When viewed through
the "color-coded" "anaglyph glasses", each of the two images
reaches corresponding eye, revealing an integrated
stereoscopic image.
2. PROPOSED ALGORITHM
Fig 1: Shows the steps for creating animated anaglyph 3D
model algorithm.
2.1 Tiles Generation for Match Resolution of Surface
and Altitude Map
To generate 3D planet surface we have used the mars surface
database which is available from public domain. The format
for altitude data is MOLA (Mars Orbiter Laser Altimeter)
taken from open database of Arizona University. The total
resolution is 46080 x 23040 pixels. In the database there are
72 tiles. Each tiles having the resolution of 7680 x 7680
pixels. And the other surface data of mars is taken from
Celestia open domain database. It has resolution of each tile is
512 x 512 pixels. Now to match both the database resolution
to create actual 3D surface of the planet, Elevation map and
surface map is expanded using interpolation algorithm to
match the resolution. The interpolated elevation map and
surface map is tiled of size 512x512 in 8192 segments each.
2.2 Tiles Stitching
Stitching is necessary when the adjacent tiles have a different
level of detail otherwise gaps in the terrain may be visible
otherwise. Adjacent tiles can have a different resolution which
causes visual inconsistencies at the joints, to avoid this we use
a stitching process for border rows and columns to avoid this.
Each tile stitches with its northern and eastern neighbors.
Stitching requires an extra row and column of indices of the
neighbor to be available to each tile. Thus, the actual tile size
used is 512×512 with its last row and column being the first
row and columns of the adjacent tiles. CPU sends separate
stitch templates to effect correct stitching.
2.3 Wireframe Rendering
The rendering process can take two forms: software rendering
(either in-house or by using licensed code) and hardware
rendering (either directly using the hardware or via an API).
The most common form used today, because of the high
availability of graphics cards capable of real-time 3D graphics,
is hardware rendering via an API such as Microsoft‟s
Direct3D/DirectGraphics. To view the 3D DirectX generated
wireframe mesh is rendered by the DEM data of the planet.
We present a scheme to render terrains, de-form them, edit
them, and perform physics involving them at real-time rates.
We use a representation that combines the fixed-size structure
of geometry clip maps and the regularity of tiled blocks. The
terrain is cached on the GPU using fixed-size rectangular
blocks. The resolution of the blocks depends on the view and
changes with height of the camera. A blocked, tiled, height-
map representation resides at the GPU cache at all times for
fast rendering and real time modification. The cache is kept
updated by sending data when needed for extent and
resolution.

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2.4 Stereoscopic Rendering
The 3D viewing anaglyph is constructed using two images
with an adequate look-angle, displayed in two colors (red and
blue, or cyan), so that viewing with red-blue filter allows one
image to be seen with the left eye (red glass) and the other to
be seen with the right eye (blue glass). As long as the stereo
separation is within limit of human viewing angle, the brain
can perceive depth in the image. Anaglyph provides a valuable
tool for visualizing the morphology of the Martian surface.
This quick visualization tool assists in selecting scenes for
labor intensive Digital Terrain Modeling.
The biggest hurdle in rendering detailed terrain data is the
large data volume. The main limitation for the number of
polygons to render was the bus bandwidth between CPU and
GPU. Every highly detailed polygon mesh needed to be
transferred over that bus. An additional limitation was the
main memory of the graphics hardware. Even when it was
managed to transfer the data, it couldn‟t be stored on the
memory of the graphics card. To be able to render a high
number of polygons on the graphics hardware, the way of how
to render high polygon meshes needed to be rethought.
For the polygon mesh several discrete LODs were created.
These discrete LODs had much less polygons. For rendering
on the GPU the low poly mesh and the different generated
LODs were used.
Stereo viewing provides added depth and realism to 3D views.
This method requires a wear of special glasses with color
filters over each eye. Best results we get, if used filters are of
complementary colors. One can visualize 3D view in stereo by
using red and blue stereo viewing glasses.
3. RESULTS AND DISCUSSION
Figure-2 shows developed application with zoom view of the
mars surface. Figure-3 shows the stepwise process of the
algorithm.
Fig 2: Mars surface zoomed view
In figure 3, it shows the generated tiles of the Mars surface data
and altitude data which is downloaded from the open source
domain. After generating tiles of equal resolution, both the data
tiles are stitched to create full surface map of the Mars.Using
the DirectX technology wireframe mesh is generated with the
DEM data of the Mars surface. Generated mesh is rendered
with the Mars surface map data. So figure also shows the 3D
visualization of the mars surface. To view in stereo 3D the map
is projected at two different angles with two different color red
and yellow for anaglyph view. Tool can also perform animated
visualization of anaglyph 3D model.

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Fig 3: Shows the stepwise process of the creating animated
anaglyph 3D model algorithm..
4. CONCLUSIONS
Uses include studies of relative and absolute surface age
chronologies, erosion processes, Analysis of Planetary Surface
and its formation Analysis of specific crater for scientific
purpose, for safe landing site identification, mineralogical
mapping of planet, development of 3D model from digital
elevation map.
ACKNOWLEDGEMENTS
While bringing out this paper to its final form, we came across
a number of people whose contributions in various ways
helped our field of research and they deserve special thanks. It
is a pleasure to convey my gratitude to all of them. I would
like to take this opportunity to express my gratitude and
heartiest thanks to Prof. R. S. Chhajed Head of the Department
of Information Technology, for his support and constant
encouragement.
REFERENCES
[1] Kiwon Lee, “A Prototype Implementation for 3D
Animated Anaglyph Rendering of Multi-typed Urban
Features using Standard OpenGL API”, Korean Journal
of Remote Sensing, Vol.23, No.5, 2007, pp.401~408.
[2] Krešimir Keresteš, “Making the Anaglyph Map”
[3] J. I. Simpson , J.R Kim b, J-P. Muller. 3D Crater
Database Production On Mars By Automated Crater
Detection And Data Fusion
[4] Tanvi Rajput. Satellite-Derived Digital Topography-
based Crater Boundary Detection and Attribute
Measurements by segmentation and Moments Measure
Techniques.
[5] Y. Sawabe, T. Matsunaga, S.Rokugawa, Automated
detection and classification of lunar craters using
multiple approaches. Advances Space Research
Volume 37, Issue 1, The Moon and Near-Earth
Objects, pp.21-27, 2006
[6] Georg Held, Alias Abdul-Rahman, Siyka Zlatanova.
Web 3D GIS for Urban Environments.
[7] http://www.mars.asu.edu/data/mola_color/ Mars
Altitude
[8] www.celestiamotherlode.net/catalog/mars.php Mars
Map
BIOGRAPHIES
Himanshu S. Mazumdar acquired his
Bachelor„s degree in Engineering in the
year 1968 and PhD in Computer
Engineering in the year 2004. He has
worked as Director, Research and
Development, Defense Training &
Technologies Champaign, IL, USA. Presently, he is working
as Professor and Head of R&D Center of Dharmsinh Desai
Institute of Technology, Nadiad, India.
Divya J Nimavat received her Bachelor„s
degree in Computer Engineering in the year
2012 and M.Tech. in Information
Technology in the year 2014. She has
worked as Researcher at R&D Center of
Dharmsinh Desai Institute of Technology,
Nadiad, India.
Marichi Patel received his Bachelor and Master of Computer
Application in the year 2009 and 2012
respectively. He has worked as Researcher
and System Developer at R&D Center of
Dharmsinh Desai Institute of Technology,
Nadiad, India.

3 d video streaming for virtual exploration of planet surface

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3 d video streaming for virtual exploration of planet surface