Visually-Pleasing Stereoscopic Imagery for Design Visualization

1. Visually-Pleasing Stereoscopic Imagery for Design Visualization Jason Walter Software Developer – Autodesk Consulting

2. Course Agenda

3. Why?

4. Better tools & technology exist “Stereoscopic Cinema failed in the 50’s because artists did not have the proper tools to produce content.” – Lenny Lipton (CTO Real-D) “Stereoscopic films take 15% more money to make. They require re-thinking the film pipeline.” – Jim Mainard (DreamWorks Technologist) “Making stereoscopic content is hard! There is little talent in the industry and we are expected to produce content for the technology.” – Phil McNally (Stereographer).

5. A better story

6. Money to be made “We have seen a trend where people are willing to spend more money to watch 3d content than 2d content” – Bob Igner (CEO Disney) “By 2010 there will be 3000 theatres equipped to project stereo content. Today only 700 exist.” – Lenny Lipton (CTO Real-D)

7. Industry is motivated “[S3D] is the most exciting thing that has happened in the business since I have been in the business.” - Jeffery Katzenberg. “I'm just going to do everything in [stereoscopic] 3D now. I'm going to shoot my daughter's birthday party in 3D.” – James Cameron

8. Why Stereo for Design Visualization?

9. Experience > Differentiate > Sell

10. Technology Overview • Display a unique perspective for each eye. • Visual processing center reconstructs in 3D. • It is just a perceptual trick.

11. Technology Overview Image from Jim Gasperini http://www.well.com/user/jimg/stereo/stereo_list.html

12. Challenges • Human visual system is very sensitive bad stereo • Traditional photographic tricks do not work • Compositing and editing must take in account depth • Not a strong understanding of stereo by artists

13. Perception of Depth

14. Depth Processing Stereopsis– depth perception using two point of views Interposition – object A is on top of object B Light and Shade – the shading of an object can provide depth cues Texture – differences in texture orientation Parallax – relative motion of different objects Perspective – vanishing points Size– relative size of objects

15. Perception of Depth with Stereoscopy (Put your glasses on now)

17. Hardware

18. Anaglyph • Cheap • Easy to find • Loss of color fidelity • Very little eye fatigue • Good for large audiences • Requires no additional hardware • Suffers ghosting

19. Glasses • Active • No ghosting • Eye fatigue • Expensive • Darker Picture • Good for small audiences • Passive • Ghosting • No eye fatigue • Cheap • Full Color • Better for large audiences

20. Checkerboard Format • Samsung DLP 3D Display

21. Horizontal Interlace • Hyundia 3D LCD

22. Full Resolution Displays • Tru3D Display (Passive) • 120 HZ CRT Displays (Active) • 120 HZ LCD Displays (Active) • REALD Z-Screen (Passive) • Projectors (Passive / Active)

23. Projectors / Cave • Christie / REALD Z-Screen • Dolby 3D • IMAX

24. Camera / Stereoscopic Cameras

25. Camera Model – Low level Confidential

26. Camera Model – Digital Parameters Confidential

27. Mapping Digital Parameters to Computer Friendly Version Confidential

28. Example of shifting & importance Film center is not necessarily aligned with optical axis. The frustum can be skewed. Confidential

29. Principles of stereoscopic cameras • It is two cameras, not one camera • Each camera is offset by a fixed distance – interaxial distance • There is a point of focus – zero parallax Confidential

30. Stereoscopic camera models • Toe-in – rotate the cameras inward • Off-axis – shifting the frustum • Parallel – focus at infinity Confidential

31. Off-axis computation from base camera model Confidential

32. Toe-in Versus / Off-axis

33. Vertical Parallax

34. Parallel Rigs • No control over convergence • As if viewing through a window • No need to worry about divergence • Easy stereo

35. Off-axis (Put your glasses on)

36. Converged (Put your glasses on)

37. Parallel (Put your glasses on)

38. Comparison (Put your glasses on)

39. Maya Stereo Demo

40. Beyond Maya’s Model • Maya’s stereoscopic camera is the base model • Provides the core parameters and calculations • Does not prevent perceptual issues • API to augment camera model • Abstraction between visualization hardware and camera Confidential

41. Maya Stereo API Properties • All cameras have a root transform – stereo rig root • Camera shape is directly below the root • Data driven approach • Attribute control how to find the data • stereoRigType • centerCamera • leftCamera • rightCamera Confidential

42. Stereo API Creation • New rigs are created via a callback script • Callback script can be MEL / Python • The callback must specify the ‘stereoRigType’ • Returns the [root, left, right] cameras Confidential

43. Simple Stereo Rig global proc string[] stereoCameraSimpleRig() { string $basename = "stereoCameraSimple"; // Create the root of the rig // string $root[] = `camera -name $basename`; string $left[] = `camera -name ($basename+"Left")`; setAttr ($left[0]+".tx") -6.32; parent $left[0] $root[0]; select -r $root[0]; return {$root[0], $left[1], $root[1]}; } stereoRigManager -add "simpleRig" "MEL" "stereoCameraSimpleRig"; Confidential

44. Guidelines

45. Two Degree Rule • No two pixels should be separated by more than 2 degrees • Maximum tolerance for human visual system (put on your glasses)

46. Two Degree Rule < 2 Degrees

47. Maya Degree Calculator - DEMO

48. Floating Window • Solves interposition issues for objects in front of ZP plane. • Artificially introduces a 3d window.

49. Floating Window

50. Maya Floating Window Calculator DEMO