CS 428: Fall 2009 Introduction to Computer Graphics Realism (overview) 11/11/2009 1
Topic overview Image formation and OpenGL Transformations and viewing Polygons and polygon meshes Programmable pipelines Modeling and animation Parametric curves (and surfaces) Procedural modeling Traditional and procedural animation Rendering 11/11/2009 2
Topic overview Image formation and OpenGL Transformations and viewing Polygons and polygon meshes Programmable pipelines Modeling and animation Rendering Object space hidden surface removal, bump mapping and other texture tricks Raytracing and radiosity 11/11/2009 3
Next few lectures Visibility (a.k.a. hidden surface removal) Object space algorithms: BSP trees, traversal, etc. Illumination and shading (recap, etc.) Bump mapping, shadows, reflection, refraction, antialising, etc. Rendering for realism Raytracing(forward, backward, distributed) Radiosity(gathering, shooting) 11/11/2009 4
Methods for realism Ensure properties of images of visual scenes are enforced many categories! Computational models of lighting + illumination (shadows, reflections, caustics) Computational models of surface properties (color, texture, fuzziness, roughness) Geometric representations (surfaces) Behavior (simulation, motion capture) Consistency of scene (global illumination) Interaction (frame rate lag, etc.) 11/11/2009 5
Methods for realism Ensure properties of images of visual scenes are enforced many categories! Computational models of lighting + illumination (shadows, reflections, caustics) Computational models of surface properties (color, texture, fuzziness, roughness) Geometric representations (surfaces) Behavior (simulation, motion capture) Consistency of scene (global illumination) Interaction (frame rate lag, etc.) Temporal and spatial anti-aliasing 11/11/2009 6
Photorealism 11/11/2009 7
Photorealism 11/11/2009 8
Photorealism 11/11/2009 9
Non-photorealism 11/11/2009 10
Polygons vs. Smooth surfaces 11/11/2009 11
Level of detail 11/11/2009 12
Level of detail 11/11/2009 13
Texture mapping 11/11/2009 14
Environment mapping 11/11/2009 15
Bump mapping 11/11/2009 16
Image-based rendering 11/11/2009 17
Motion capture 11/11/2009 18
Simulation 11/11/2009 19
Trade-off(s) Lots of computation to do Trade-off(s) Quality vs. computation time Quality vs. [cost, staff of artists, etc.] Quality vs. [insert some resource here] Real-time vs. off-line 11/11/2009 20
Sweet spot Highly application dependent Special effects Games Virtual reality Computer aided design (CAD) Desired effect non-photorealistic rendering 11/11/2009 21
(Extreme) visual abstraction 11/11/2009 22
Uncanny valley Bukimi no tani The uncanny valley. Masahiro Mori 1970 11/11/2009 23
Uncanny valley Solved? 11/11/2009 24
Uncanny valley Solved? 11/11/2009 25
Uncanny valley State of the art Still images are continuously improving Just a matter of time. Potentially solvable. Problem is exacerbated in human animation Motion capture works for film. Infeasible for physical interaction in games. Much research effort. Potentially solvable. But what about digital interaction? 11/11/2009 26
Historical development [Rendering.] [Animation.] [Interaction.] 11/11/2009 27
Uncanny valley of Interaction Currently, meaningful interaction in photorealistic environments is quasi nonexistent. Limited to. Destruction. Shooting. Etc. Notable example. Exploration. Sense-pleasure as a goal is possible. Explicit interaction goals other than the most primitive kind are generally absent. Other Direct interactions? Indirect interactions/simulations? 11/11/2009 28
Visual interaction Abstraction The Marriage. Rod Humble 11/11/2009 29
Simulated Reality Abstraction Gravitation. Jason Rohrer 11/11/2009 30
Realism What is reallies in the eye of the beholder In order of increasing difficulty to get right Still images Animations Interactions No fixed rules It s all simulated anyway, and the sky is the limit 11/11/2009 31