2. BPC: Art and Computation – Fall 2006 Introduction to virtual environments Glenn Bresnahan glenn@bu.edu

3. BPC: Art and Computation – Fall 20062 Outline High level overview of VR hardware and software (details will be covered throughout the year) –Demonstration of a VR world –3D Display Wall – how we see in 3D –Animation –Rendering –DAFFIE VR software environment

4. BPC: Art and Computation – Fall 20063 Intro to demo – physical environment 3D Display Wall –Stereoscopic –3D glasses Navigation –Game controller –Left joystick: Moves U/D Moves R/L –Right joystick: Moves F/B Turns P(L)/S(R) –Start button: reset

5. BPC: Art and Computation – Fall 20064 Intro to demo - virtual environment Multi-person, multi-site shared virtual space –Navigation –Avatar representation –Telephony

6. BPC: Art and Computation – Fall 20065 3D Display – stereopsis Stereoscopic display –Stereopsis – left and right eye view

7. BPC: Art and Computation – Fall 20066 Stereoscopic display Viewmaster

8. BPC: Art and Computation – Fall 20067 3D display - polarization Light is a wave

9. BPC: Art and Computation – Fall 20068 3D display - polarization Polarization aligns light in a plane

10. BPC: Art and Computation – Fall 20069 3D display - polarization Polarizing filters used to align light Filters rotated 90 degrees block light Two projectors, one per eye view –Polarizing filters rotated 90 degrees –Matching glasses

11. BPC: Art and Computation – Fall 200610 3D stereoscopic displays – other techniques Colored (red-blue) glasses –Anaglyph Circular polarizer Shuttered glasses Dual (head-mounted) display

12. BPC: Art and Computation – Fall 200611 Animation What is animation? Animate: to give life to; to bring to life

13. BPC: Art and Computation – Fall 200612 Animation What is animation? Traditionally applied to cartoons Creation of apparent motion from still images

14. BPC: Art and Computation – Fall 200613 Animation – pictures in motion

15. BPC: Art and Computation – Fall 200614 Animation – component images

16. BPC: Art and Computation – Fall 200615 Animation - principles Creating moving image from a sequence of still images –Each image is displayed for a fraction of a second Basis for film, video, computer graphics, etc.

17. BPC: Art and Computation – Fall 200616 Animation – traditional Each image (cell) was hand drawn

18. BPC: Art and Computation – Fall 200617 Animation – film and video Film – individual images (frames) are photographically reproduced on film strip Video – individual images (frames) are recorded or transmitted as electrical signals

19. BPC: Art and Computation – Fall 200618 Animation – computer graphics Computer generates individual images (frames) and displays them rapidly on a monitor –Technology is very similar to video –Images may also be recorded to film (e.g. CG special effects) or video

20. BPC: Art and Computation – Fall 200619 Rendering Creation of a pictorial representation –Generally applied to a realistic depiction of a 3D scene or object Types of rendering –Artistic rendering –Photographic rendering –Computer rendering

21. BPC: Art and Computation – Fall 200620 Artistic rendering Rendering realistic images (perspective)

22. BPC: Art and Computation – Fall 200621 Artistic rendering Trompe l’oeilGone bad

23. BPC: Art and Computation – Fall 200622 Photographic rendering Camera and film

24. BPC: Art and Computation – Fall 200623 Photographic rendering Camera obscura

25. BPC: Art and Computation – Fall 200624 Computer rendering (3D) Computer creates an image from a model A model is a (mathematical) description of the 3D object

26. BPC: Art and Computation – Fall 200625 Computer rendered image

27. BPC: Art and Computation – Fall 200626 Computer rendering (3D) Computer takes into account the position of the object, as well as the position of the viewer (simulated or virtual camera). Computer will shade the objects based on position of lights and the surface's material properties.

28. BPC: Art and Computation – Fall 200627 Computer rendering process

29. BPC: Art and Computation – Fall 200628 Computer models Conceptually like a blueprint

30. BPC: Art and Computation – Fall 200629 Computer models

31. BPC: Art and Computation – Fall 200630 Computer models begin./table/items setxfm 1.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 1.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 1.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 1.000000e+00 putprp cull 1 begin./table/items/cube polygon setxfm 1.500000e+00 0.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 1.500000e+00 0.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 1.500000e+00 0.000000e+00 2.000000e+00 -1.500000e+00 -1.250000e+00 1.000000e+00 defpnt 1 -1.000000e+00 -1.000000e+00 -1.000000e+00 defpnt 2 -1.000000e+00 1.000000e+00 -1.000000e+00 defpnt 3 1.000000e+00 1.000000e+00 -1.000000e+00 defpnt 4 1.000000e+00 -1.000000e+00 -1.000000e+00 defpnt 5 -1.000000e+00 -1.000000e+00 1.000000e+00 defpnt 6 -1.000000e+00 1.000000e+00 1.000000e+00 defpnt 7 1.000000e+00 1.000000e+00 1.000000e+00 defpnt 8 1.000000e+00 -1.000000e+00 1.000000e+00 defpoly 1 2 3 4 0 defpoly 8 7 6 5 0 defpoly 3 7 8 4 0 defpoly 2 1 5 6 0 defpoly 2 6 7 3 0 defpoly 1 4 8 5 0 putprp color 3ff end./table/items/cube

32. BPC: Art and Computation – Fall 200631 Computer animation Generate multiple images by changing the viewing (i.e. camera) position Reposition one or more objects between frames

33. BPC: Art and Computation – Fall 200632 Computer animation Render a sequence of models

34. BPC: Art and Computation – Fall 200633 Computer animation

35. BPC: Art and Computation – Fall 200634 DAFFIE Software DAF FIE D istributed A pplications F ramework F or I mmersive E nvironments Glenn Bresnahan Erik Brisson Robert Putnam

36. BPC: Art and Computation – Fall 200635 What is VR/VE Definitions –Immersive, natural interaction, believable Characteristics –3D appearance –Stereoscopic display –Large display, wide field of view –1 st person view –Navigation within 3d space (natural interface) –Response to physical position of viewer –Realistic audio

37. BPC: Art and Computation – Fall 200636 DAFFIE Worlds Multiple participants –Represented by an avatar –Interact with each other Telephony –Interact with virtual objects Shared virtual space –All participants experience the same virtual world

38. BPC: Art and Computation – Fall 200637 DAFFIE Worlds rooms Shared space divide into rooms portals Doorways (portals) between rooms objects Rooms contains objects Objects model –3D appearance (3D model) sequences –May be animated (sequences of models) textures –May have an appliquéd (2D) image (textures) audio –May have associated sounds (digital audio) agents –May react to avatars (people) or other objects (behaviors via agents)

39. BPC: Art and Computation – Fall 200638 DAFFIE Worlds – Using images Images may be appliquéd to the surface of an object

40. BPC: Art and Computation – Fall 200639 DAFFIE Worlds – Using images Objects may be flat or curved Images may be animated by using a sequence of images

41. BPC: Art and Computation – Fall 200640 DAFFIE Software Components 3D viewer Sound server –Telephony –Audio mixer & player Navigation Behavior agents Audio/video generators/processors Object generators/manipulators DAFFIE components communicate over the network

42. BPC: Art and Computation – Fall 200641 DAFFIE Software Environment viewer behavior agent sound player viewer telephony sound player behavior agent behavior agent event server

43. BPC: Art and Computation – Fall 200642 DAFFIE Viewer Supports multiple display devices from workstations to CAVEs Directly supports advanced input devices (3D trackers, wands, etc). Simple script-based world description –Geometric models –Animation –Sounds Many 3D model formats Local control of time-sensitive animation and sound Broadcasts avatar motion and object state information to other components

44. BPC: Art and Computation – Fall 200643 DAFFIE Sound Server Provides telephony between participants Mixes and plays multiple sound sources –Real-time audio streams (e.g. telephony) –Prerecorded object sound files Sound is localized in 3D space –Originates at 3D virtual object location –Heard relative to the avatar’s position –Played relative to listener position in physical space (when tracked) Sound player output –Multi-channel localized audio signals which can be played into a speaker array

45. BPC: Art and Computation – Fall 200644 DAFFIE Navigation Advanced device support built-in to the viewer Windows-based navigation client –Game controllers –Hand-held pointing devices (Gyro Pointer) –Mouse –Keyboard Can control one or more avatars

46. BPC: Art and Computation – Fall 200645 DAFFIE Behavior Agents Control object behavior Proximity triggers Portals Device interfaces –Kinematic sculptures Video sourcing (camera) Audio and video processing