Optimization for Making Stereoscopic 3D Games on PlayStation® (PS3™)
- 1. Sébastien Schertenleib Principal Engineer Sony Computer Entertainment Europe Research & Development Division Optimization for Making Stereoscopic 3D Games on PlayStation® (PS3™)
- 2. Slide 2 • Stereoscopic 3D (S3D) Games Overview • How Stereoscopic 3D Works • PS3™ Implementation of S3D Games • Reprojection • SPU Optimisation • Case Studies Outline
- 3. Stereoscopic 3D Games Overview
- 4. Slide 4 • Movie – Digital animation – Actors • Broadcast – VOD – FIFA World Cup 2010 • Professional – Digital cinema camera • Home – TV and projector – BD player/recorder – BD movie – Digital camera – Stereoscopic gaming on PlayStation®3 Sony’s Approach to Stereo 3D
- 5. Slide 5 • Increased immersion • Some tasks are easier (driving, batting, ...) • New types of games may become possible (first person sports?) Why is Stereoscopic 3D Important to Games?
- 6. Slide 6 • 3D TVs now in the home • 3D works very well in close proximity • Gamers tend to demand more immersion – never less • Wide variety of 3D content should sustain momentum (sports, movies, games, TV, photos, home movies) 3D is here to Stay!
- 7. Slide 7 • All S3D displays send a different image to the left and right eye • There are several different technologies in use • The main ones are – Anaglyph (Red Cyan Glasses) – Passive (Polarized Glasses) – Active ( Shutter Glasses) – Auto-Stereo ( No Glasses) S3D Displays
- 8. Slide 8 2D = 1 camera generates an image which is displayed on the TV screen and is then seen in both eyes 3D = 2 cameras generate 2 images (one for each eye) which are displayed on a 3DTV screen, then separated by special glasses to the correct eye. How 3D works 2D 3D Cameras Images TV screen Glasses Image seen
- 9. Slide 9 • Red Cyan Glasses – Cons • Only really works for black and white – Pros • Easy to make content for • No special display needed – Not recommended for commercial titles – Useful for research • Works anywhere Anaglyph
- 10. Slide 10 Absorptive Polarizer • Uses 2 projector lenses, one for each eye – Lens are polarized differently – Polarized glasses de-mulitplex signal at your eyes – Passive cinema projection requires a special "non-depolarising" screen • For front projection, this is normally metallic silver. Passive Glasses (Movie Theatre)
- 11. Slide 11 • TV Surface is coated with a polarized filter – Some parts of the TV are seen by the left eye – Some parts of the TV are seen by the right eye • Half the resolution of the image is lost • Viewing angles can be limited • Cons – Lose resolution to mask – Screen filter adds to TVs cost • Pros – Glasses are cheap Passive Glasses (TV)
- 12. Slide 12 • The TV updates @ N*120Hz • Alternate left and right images • Shutter glasses synchronization with TV to mask the left and right frames Active Glasses
- 13. Slide 13 • This is the solution used in most of the new S3D TV shipping now – Including Sony BRAVIA • Pros – Full HD to each eye – Wide range of viewing angles • Cons – Glasses need batteries and are more expensive Active Glasses
- 14. Slide 14 • These require no glasses to operate – Current solutions use a parallax barrier or lenticular technology • Generally the viewing angles are limited Auto-stereo Displays
- 15. Slide 15 • HDMI 1.4 introduces a standard on both ends • PS3™ supports S3D via 3D over HDMI – It will work on every HDMI 1.4 receiver (e.g. 3DTV) Connectivity
- 16. Slide 16 • The PS3™ outputs the following formats for S3D Supported Formats used by PS3™ Use Resolution (Per Eye) Hz BD Playback 3D Photo Browsing (PlayMemories) 1920*1080p 24 Games 1280*720p 60
- 17. Slide 17 • Stereoscopic 3D (S3D) Games Overview • How Stereoscopic 3D Works • PS3™ Implementation of S3D Games • Reprojection • SPU Optimisation • Case Studies Outline
- 18. How Stereoscopic 3D Works
- 19. Slide 19 • Stereoscopic 3D games require to setup two cameras, one for each eye • A naïve implementation can deteriorate the 3D experience Setting up the 3D Cameras
- 20. Slide 20 Translate the cameras in 3D space L R Setting up the cameras Attempt 1: Simple Offset Large portion of each image is only visible to a single eye resulting in considerable eye strain. Result: Failure
- 21. Slide 21 Translate the cameras in 3D space L R Setting up the cameras Attempt 2: Toe-in Convergence is not parallel with the screen which causes vertical parallax deviations. These deviations are unnatural and make the experience uncomfortable. Result: Failure
- 22. Slide 22 Translate the cameras in 3D space L R Setting up the cameras Attempt 3: Parallel Projection The projection matrix is changed so that the projection is asymmetric. No vertical parallax and acceptable portions of the scene are only visible to a single eye. Comfortable to view for an extended period of time. Result: PASS − −− + − + − − + − = 0100 2 00 0 2 0 00 2 fn nf fn fn bt bt bt n lr lr lr n Moblic
- 23. Slide 23 Translate the cameras in 3D space Real World A B Screen Plane I θ S α View Space Legend • I: camera separation • S: distance to viewing plane • Z : screen distance • θ : horizontal field of view • α : angle of convergence i D Z d W View Space z ( ) dI ID Z ziW d − × = − = )2tan(2 )tan(2 θ α )tan(2 )tan()2tan( α αθ Si WIr = ×=×× ( ) zrrS z DZ zSIrd )1( 1 −+ ×= −××= Theorem Variable Definition Derivation Real World Legend • i: eye separation • D: distance to display • d: amount of parallax • W: display width • Z: Depth of the object
- 24. Slide 24 • When you look at an object – Both eyes are aiming directly at the object – For a distant object the eyes are almost parallel – For a close object the eyes must toe inward Convergence See how the girl’s convergence angle decreases as the bear gets more distant
- 25. Slide 25 • When viewing S3D your eyes are focused on the screen – But converging at a different depth • Accommodation and Convergence can be decoupled Accommodation and Convergence Accommodation Convergence
- 26. Slide 26 • Perceived depth from separation in images • Positive Parallax – behind screen • Zero Parallax – on screen plane – left and right images are same • Negative Parallax – in front of screen Perceived Depth
- 27. Slide 27 • Same image with same separation in both diagrams • Perceived depth is affected by viewer position • Further back gives more perceived depth with less convergence Where You Sit Matters
- 28. Slide 28 • Everything moves closer • Everything decreases in size • Objects in the foreground move further away • Objects in the foreground increase in size • Objects in the distance are unchanged Placement and Scaling in Stereoscopic 3D Decrease the convergence Decrease the interaxial x y x y z
- 29. Slide 29 • Incorporating a 3D strength slider into your title is recommended – Slider should go from Max down to 0 • This gives players the chance to reduce the stereo effect to a comfortable level – Screen size and distance from screen as well as personal taste 3D Slider
- 30. Slide 30 • Scaling both the convergence and interaxial by the same amount – Stretch or squash the depth but maintain the (2D) size of objects at point of convergence – Use in our 3D slider implementation • If both interaxial and convergence are set to zero, you get a 2D picture Keeping Object Size Display Perceived Depth 2DMax
- 31. Slide 31 • The TV is a window – Most content will be inside the TV – Content in front of the TV will be • Small and Fast Generally – Avoid Window Violations • Occurs when an object touches the stereo window resulting in cutting off more of an object in one eye than the other Stereo Reference Screen Space Audience Space Image plane Stereo Infinity Uncomfortable Stereo Comfortable Stereo Comfortable areas for 3D stereo Red is bad Blue is good
- 32. Slide 32 Calculating Frustum Origin Z = S / ( 1 + W / I ) Legend • Z : frustum origin • S: distance to viewing plane • W : width of viewing plane in view world • I: camera separation L R Screen S W I Z Monoscopic Frustum Culling
- 33. Slide 33 Calculating Frustum Origin Z = S / ( 1 + W / I ) Legend • Z : frustum origin • S: distance to viewing plane • W : width of viewing plane in view world • I: camera separation L R Screen Steroscopic Frustum Culling S W I Z Reduce window violations
- 34. Slide 34 COMFORT ZONE The limitations of parallax – the acceptable limits
- 35. Slide 35 The limitations of parallax - divergence
- 36. Slide 36 • Ensure +ve parallax is less than 1 degree • Work for wide variety of screen size from mobile to theatre and HDTV • Typical screen the maximum depth is approx. the same as viewing distance • Including a 3D strength slider is useful Parallax Management – use an arbitrary value
- 37. Slide 37 • Alternatively using PlayStation®Eye and Face tracking, it is possible to measure the exact viewer distance – Combine with the screen size (HDMI1.4), we could guarantee the best parallax for each user setup • Installed base of millions of cameras and growing – With the introduction of the PlayStation®Move motion controller PlayStation®Eye
- 38. Slide 38 Limiting the positive parallax: how the depth is perceived Accurate depth but large restrictions on the game design real world viewed world max parallax
- 39. Slide 39 • Cross Talk or Ghosting can become very evident if there is too much separation between images – Most of this is inherent to the display technology • Latency in the panels and glasses – Some is due to separation in the images • Left and right images are very different at extremes of negative and positive parallax • Eyes and brain start to realize they are being tricked… Separation: Cross Talk
- 40. Slide 40 • Major drawback with current shutter glasses technology (sync-errors, inability to block all the light,...) – The L/R eye see some residue of the image dedicated to the R/L eye – Large contracts increase this behaviour Crosstalk
- 41. Slide 41 • Stereoscopic 3D (S3D) Games Overview • How Stereoscopic 3D Works • PS3™ Implementation of S3D Games • Reprojection • SPU Optimisation • Case Studies Outline
- 42. PS3™ Implementation of S3D Games
- 43. Slide 43 • Frame packing method of 720p at 59.94Hz • Extended APIs for stereo 3D – Tells you if the TV supports 3D – Gives you the screen size – Choice to switch to 3D is up to the user from within your game • Sample code & documents PS3™: Stereoscopic 3D Support
- 44. Slide 44 • New Initialization Code for S3D TV modes • UI to switch to and from S3D including strength slider • Extra legal screen • Cameras with asymmetric view frustums • New frame buffer scheme containing full resolution buffers for both eyes • Render everything twice with exactly the same state information at target frame rate Stereoscopic Rendering
- 45. Slide 45 • Output Mode for 3D Game is 1280x1470 1280 pixels 720 pixels 720 pixels 1470 pixels Left Right 30 pixel gap filled with black colour
- 46. Slide 46 • Need to render most things twice • Need to use appropriate 3D settings • Need to separate update and render • Use a well placed 3D HUD • Plan from the start Converting a Game to S3D
- 47. Slide 47 • Rendering two images from the same hardware may require compromises or limit the possibilities – Performance • The scene must be rendered twice. – Video memory (VRAM) usage • The frame buffer may be larger in some cases – Resolution limits • More pixels may be processed Technical Consideration
- 48. Slide 48 • Need to traverse the scene for two cameras • Graphics Command Buffer will grow as more data is involved (ModelViewProj matrix, viewport…) CPU Overheads
- 49. Slide 49 • The scene has to be rendered twice • Double vertex processing – Large fillrate and memory bandwidth requirement GPU Overheads
- 50. Slide 50 • When fill-rate is an issue: – Hardware horizontal upscaler can help • Supported frame buffer resolutions • Reduces memory and fill requirements • Or use a different approach such a reprojection – More on that later Any help? Width 1280 1024 960 800 640
- 51. Slide 51 • Rendering to lower resolution buffers with AA looks better than high resolution buffers with no AA • Reduces High frequency noise – Stair casing, “jaggies” , edge sparkle – May not match in both eyes – Can be misinterpreted as depth cue or movement Resolution Vs. Anti-aliasing
- 52. Slide 52 Ouch!! • Monoscopic games – Wait for the next vertical blank – Immediate flip • Might leads to higher FPS but also screen tearing • Stereoscopic games – Must wait for next vertical blank • Else get tearing in one eye only Swapping the Buffers
- 53. Slide 53 • If the data is not synchronized artifacts will be visible Same Scene, Both Eyes While(notdead) { updateSimulation(time); render(); vsyncThenFlip(); }
- 54. Slide 54 • If the data is not synchronized artifacts will be visible Same Scene, Both Eyes While(notdead) { updateSimulation(time); render(LeftEye); render(RightEye); vsyncThenFlip(); }
- 55. Slide 55 • Share Common Objects – View independent render targets (shadow map...) • State caching – Big saving for both CPU and GPU Optimization While(notdead) { updateSimulation(time); renderShadows(); renderPlayers(); renderHUD(); vsyncThenFlip(); }
- 56. Slide 56 • Share Common Objects – View independent render targets (shadow map...) • State caching – Big saving for both CPU and GPU Optimization While(notdead) { updateSimulation(time); renderShadows(); renderPlayers(LeftEye,RightEye); renderHUD(LeftEye,RightEye); vsyncThenFlip(); }
- 57. Slide 57 • Shadow maps are independent of view – Cache shadow depth map for both eyes • Reflections are view dependent – May still have to render for each eye depending on how much detail is present Shadow Depth and Reflection Maps
- 58. Slide 58 • Render once for both eyes – Shadow Map – Spot light maps projected in the scene • Render once per eye – Back Buffer – Depth Stencil Buffer – HDR – Blur – Bloom – Mirroring – Parallax mapping – Depth of field – ... 3D Rendering Strategies
- 59. Slide 59 • Instead of rendering entire scene into the left buffer, then the right buffer – Flip flop between render targets to reduce state changes • There is a cost associated with swapping render buffers though – Pipelines have to clear out – Choose granularity carefully – Alternatively, change the viewport / clip planes Alternating Render Targets
- 60. Slide 60 • Avoid Billboard – Distant billboard parallel to screen are okay • Avoid scintillating pixels – Use texture filtering and anti-aliasing – Avoid film grain effects • Avoid large untextured areas – Lack of depth cues (“cardboarding”) • Sky filled with plenty of clouds > Blue sky • Bump mapping – Flatness will ruin the effect Visual Quality problem areas
- 61. Slide 61 • View dependant effects – Reflections • Difference of contrast for each Eye – Some Tone Mapping implementation – Might produce the Pulfrich effect • Telephoto lenses can cause objects to appear flattened into layers • Fast action – When using stereoscopic viewing, the brain needs a small amount of time to register the effect Visual Quality
- 62. Slide 62 • Can be distracting in S3D • Ideally on or very near the screen plane – Consider using depth and transparency – Maybe some elements can be raised slightly to add visual interest Stereo Design: HUD
- 63. Slide 63 • Some HUD elements will not work correctly in S3D compared to 2D – Cross hairs are inherently 2D – You aim a gun with one eye creating a transit between the target, eye and cross hairs – Placing the Cross hair in the scene at the correct depth solves this problem – Or use a laser targeting system • Looks great in S3D Stereo Design: HUD
- 64. Slide 64 • Some post-processing effects may have to be tuned for S3D – For instance prefer motion vectors over motion blur – Use depth of field cautiously (more difficult to focus in 3D) Stereo Design: Post-Effect
- 65. Slide 65 • Sudden video cuts to images with their focal points at different depths can be tiring for viewers • Try to keep focal point of images at the same depth between cuts • Can adjust at run time by moving Zero Parallax Plane – Convergence blending Stereo Design: Video Edits time Bad Example Better Example time
- 66. Slide 66 • Depth budget over time – Allow some less depth intensive period – User can rest and enjoy even more climax in full 3D Stereo Design: Dynamic Depth Intensity 0 50 100 Depth Intensity
- 67. Slide 67 • Place a frame in the scene with more negative parallax than the closest object – Creates the illusion of moving the surface of the screen forward • The window appears to float in front of the screen Window Violations and Dynamic Floating Windows Floating Frame Window Violation
- 68. Slide 68 • Avoid that one object becomes more visible by one eye Dynamic Floating Windows Left Image Right Image Left Image Right Image Floating Window Floating Window
- 69. Slide 69 • Static floating windows look obvious • Dynamic Floating windows are a lot more subtle – Use in many movies Dynamic Floating Windows
- 70. Slide 70 • Possible to have a lot of fun with floating windows in UI design Window Violations and Floating Windows
- 71. Slide 71 • Simplify assets and shaders • More aggressive LOD • Remove small objects or some post-effects • Reduce the game video resolution – The human visual system does not just use the differences between what each eye sees to judge depth. It also uses the similarities to improve resolution ☺ Stereoscopic Vs. Monoscopic Version
- 72. Slide 72 • Write to both left and right scenes in a single pass – Some post-effects • Colour enhancements • Crosstalk reduction • … – Objects at screen level • Part of the HUD Sharing Processing via MRT-2 Input Texture Fragment Program MRT0 MRT1 GPU Render Target Right Scene Left Scene
- 73. Slide 73 • “Ortho-stereo” viewing/head- tracked VR – This can produce a stunningly realistic, hologram-like effect for a single viewer as they move around the room • PlayStation®Eye – libFace, libHead • PlayStation®Move – Movement in 3D space (Z axis) Going One Step Furtherviewer screen asymmetric fields of view dynamic viewing frustum
- 74. Slide 74 • Can overcome issues arising from depth perception or divergence • Improve the 3D effects on areas the user is likely to focus (character)s Non Disparity Mapping for S3D Reference: Lang, M., Hornung, A., Wang, O., Poulakos, S., Smolic, A. & Gross, M. (2010, July). Nonlinear Disparity Mapping for Stereoscopic 3D
- 75. Slide 75 • Stereoscopic 3D (S3D) Games Overview • How Stereoscopic 3D Works • PS3™ Implementation of S3D Games • Reprojection • SPU Optimisation • Case Studies Outline
- 76. Reprojection
- 77. Slide 77 • Rendering the entire scene can be prohibitive – Might lead to difficult trade off • 60Hz game or split-screen game – 30Hz in S3D should be doable • Reduce scene complexity for S3D build – Lower resolution, less details, disabling effects, etc Something less depressing? • Perhaps! ☺ Rendering Twice
- 78. Slide 78 • A screen space algorithm would be appealing – Fixed run-time cost, independent of scene complexity ☺ – Might make S3D possible with fewer limitations How to Reduce the Burden?
- 79. Slide 79 • If we have a frame buffer and a Z buffer • Possible to generate the other eye view from this as a post processing step • No need to re-architect the rendering pipeline for S3D • Could be faster than traditional methods • Don’t have to render everything twice What About Automated Stereo Conversion?
- 80. Slide 80 • Parallax from depth map – Render a single image – Create the second image using the depth map and colour separation – Pro: • <2ms on RSX™ – Cons: • Large parallax creates gaps which need to be backfilled (borders) • Transparency and reflections won’t work • Use proximity – Raw occlusion queries Alternative Ways of Creating Stereoscopic 3D
- 81. Slide 81 • Apply a depth-dependant parallax shift • Image-space operation creating the right image from the left image Reprojection
- 82. Slide 82 • An image rendered using one view-projection matrix can be remapped pixel by pixel to a second view-projection matrix – In our case, we only need a x-axis depth- dependant offset • Offset is based on a linear function using the Z value stored in the depth buffer and the stereo camera parameters Reprojection Matrix
- 83. Slide 83 • Scanline the RGBA colour buffer and depth buffer – Each input pixel will write a single output pixel • Lead to small cracks when depth changes • A second pass will then back-fill any such gaps Reprojection
- 84. Slide 84 Reprojection Effect code Func(depth, cameras, InputPixelColor) Input pixels from the color buffer and depth buffer Output pixel Colour Buffer Depth Buffer Left Right
- 85. Slide 85 • Read depth value • Calculate pixel offset using the linear function func(z, camParams) • Read RGBA pixel • Write pixel to intermediate buffer at offset location (Xdest = X+offset) 1st Pass: Reprojection Per-pixel
- 86. Slide 86 Reprojection Gaps will be created at depth disparity Invalid Pixels Left Right
- 87. Slide 87 • Read intermediate output buffer • If pixel is invalid, use most recently read valid pixel value • Pack and write pixel to output RGBA scanline 2nd Pass: Back-fill per pixel
- 88. Slide 88 Reprojection Invalid Pixels Back-fill Pixels Remove the Gaps!
- 89. Slide 89
- 90. Slide 90 • Works surprisingly well with sensible stereo strength • Great quality with positive parallax – No major image artefacts for opaque objects – Transparent objects look acceptable – Slight stretching at screen edges (easy to overcome) – Works with negative parallax (objects coming out) Screen Space Reprojection
- 91. Slide 91 • Transparent and reflection are incorrect • Can create small cracks with depth changes • Side band – Black bars on the left and right side of the screen • Hardly noticeable with TV with black borders • Or extend the display buffer by x pixels (where x depends on depth separation) Limitations
- 92. Slide 92 • MSAA can lead to artefacts due to the depth discontinuities – MLAA is less affected • Objects that lead to large disparity between both views should be render twice – View dependent shading is not handled by the reprojection operation – Post-Effects • Normal case is rendered via reprojection Gotchas
- 93. Slide 93 Generating two images • Heavy GPU overheads – Potential trade-off with game resolution and scene complexity • Results are correct also for view dependent effects Reprojection • Artefacts visible at depth discontinuity or for view dependent effects – Can be minimized but require change in the renderer • Possible cardboarding • Screen space effect with reduced impact on the performance – Allow to keep higher in-game resolution Comparison
- 94. Slide 94 • Trioviz, Darkworks • UE3 (via Trioviz), Epic Games • CryEngine 3, Crytek • … Out-of-the Shelves Solutions
- 95. Slide 95 • Stereoscopic 3D (S3D) Games Overview • How Stereoscopic 3D Works • PS3™ Implementation of S3D Games • Reprojection • SPU Optimisation • Case Studies Outline
- 96. SPU Optimisation
- 97. Slide 97 • SPU can contribute to graphics and offload RSX™ • Possible to take into account similarities between both views – E.g.: conservative occlusion queries SPU Optimization for S3D
- 98. Slide 98 • Gross frustum culling is really important on the RSX™ – Anything not sent for rendering is a win – Doubly important when rendering in stereo • Frustum culling is fairly easy to move to SPUs – Testing boxes or spheres against 6 planes – Helps the performance of the 2D version of your game too – A lot of bang for your buck Frustum Culling
- 99. Slide 99 • Left and Right eyes should be seeing almost the same scene • Use single composite frustum for testing – Extract planes from camera matrices • Once this render list is created it can be used for both eyes – Saves CPU time Frustum Culling
- 100. Slide 100 • Very popular via PlayStation®Edge – Can be customized for S3D Geometry Culling On SPU L R e L R N Vl(Xl,Y,Z) Vr(Xr,Y,Z)
- 101. Slide 101 • Using Xl = Xr-e, we can potentially early reject or accept both faces Backface Culling ZCYBeXrAXrAMax CBANZYXrVrCBANZYeXrVl **))(*,*( 0),,(),,(&&0),,(),,( −−>− >•>•− . Front-Facing for Left Eye only Front-Facing for both Eye Front-Facing for Right Eye only Back-Facing for both Eyes
- 102. Reprojection on SPU
- 103. Slide 103 • Copy tiled color buffer and depth buffer to linear system memory using RSX™ • Kick SPU jobs • Sync on SPU results • Copy the result back to VRAM Reprojection on SPU
- 104. Slide 104 Pipeline Render left eye main Copy Reproject Render left eye problem objects RSX Copy RGBA and depth buffers to host Copy Render right eye problem objects Left eye render complete Right eye render complete SPU Host RAM RGBA + D24S8 Result buffers Sync RSX/SPU Sync RSX/SPU
- 105. Slide 105 • Buffers transfer Host RAM <> VRAM is linear to buffer size • Reprojection on SPUs is fast • The whole process take around 7.5% (~2.5ms) of a 30hz frame at 720p – Buffer transfer (color + depth/stencil): ~0.4ms each way for 720p (~1.6ms) – ~0.7ms for SPU jobs (on all 6 SPUs) Performance
- 106. Slide 106 • In many cases, the latency is completely hidden as RSX™ is rendering the problematic objects for the left eye How to Hide Latency for RSX™
- 107. Slide 107 • Stereoscopic 3D (S3D) Games Overview • How Stereoscopic 3D Works • PS3™ Implementation of S3D Games • Reprojection • SPU Optimisation • Case Studies Outline
- 108. Case Studies
- 109. Slide 109 • 2D version: 1080p@60Hz • S3D version: 720p@30Hz – (1280*720*2) = 1.7Mpixels – (1920*1080) = 2.1Mpixels • Fixed interaxial distance • Max separation of 3% WipEoutHD
- 110. Slide 110 • Some work on the HUD – Push cross hairs into scene • Add S3D elements to Menus to keep the game feeling S3D – Else it was very noticeable when the game was only displaying 2D graphics in menus WipEoutHD
- 111. Slide 111 • 2D version 720p@30Hz (dynamic framebuffer) • No scope for cutting frame rate • Game already had split screen view – Pushes out LOD and fewer effects • Bound by fill rate – Used smaller render targets • In car view uses fixed interaxial • Chase came uses varying interaxial – Quite wide settings to emphasize depth in the scene Motorstorm: Pacific Rift
- 112. Slide 112 • Lowered HUD opacity • Easy for player to filter on depth – Look at HUD – Look through HUD Motorstorm: Pacific Rift
- 113. Slide 113 SuperStardustHD • 2D version at 1080p@60hz • 3D version at 720p@60hz – No compromise in the game assets (share for 2D/3D version) – Conversion made possible via optimization
- 114. Slide 114 • Negative parallax (out of screen) SuperStardustHD
- 115. Slide 115 • Generating two separate images – Sometime using half-height screen buffer and the HW upscaler – Combine with anti-aliasing produces excellent results in 3D – Process is easier if the game support split screen • Reprojection – Good trade-off quality / performance Different Ways to Convert to S3D Split screen > L + R Reprojection
- 116. Slide 116 Cost of 3D Game Development 3D Conversion Overheads: • KillZone 3: 2% • Hustle Kings: 2% • The Fight: <1% • MotorStorm Pacific Rift: 2% • WipeoutHD: 1% Will still require a few man months, especially for tweaking the results Total Cost Typical 3D Conversion cost
- 117. Slide 117 • Stereoscopic 3D (S3D) Games Overview • How Stereoscopic 3D Works • PS3™ Implementation of S3D Games • Reprojection • SPU Optimisation • Case Studies Outline
- 118. Conclusion
- 119. Slide 119 • Stereoscopic 3D games require less than twice the amount of processing – Some elements can be rendered once – Reprojection is a fair technique • Making Stereoscopic 3D content looks good require some tuning • Stereoscopic 3D should be comfortable to experience – Always visually check on a full sized screen Conclusion
- 120. Slide 120 • SCEE R&D • WWS Stereoscopic 3D Team • SCE Worldwide Studios (1st & 2nd Party studios) Acknowledgments