Post on 31-Dec-2015
description
NPR(Non-photorealistic
Rendering)
Billy Davidson
CS 395 Advanced Graphics
January 22, 2004
Non-photorealistic Rendering
Most computer graphics work strives for photorealism
Other types of depiction can be more expressive or artistic
Depict intrinsic or extrinsic properties?
Terminology
Image Picture Intrinsic/Invariant Extrinsic Constancy
Constancy
We do not experience some extrinsic properties of the image we see
3D -> 2D Mappings
Sketches by 7-year old children
Depiction
Depiction is the mapping of properties of the scene to properties of the picture
Traditional 3D -> 2D geometric projection is only one possible meaningful mapping
Projections
Different projections preserve different intrinsic properties
Vision as Inverse Problem
V() = “Visual reaction” function Not invertible due to ambiguity, emotional
factors, etc.
Primary vs. Secondary Space
Respect local rules but not global ones
Primary vs. Secondary Space
Tone mapping
Representation Systems
Spatial system Primitive system Attribute system Mark system
Painterly Rendering
Tarzan
Pen Strokes
Bones
Cel Shading
The Legend of Zelda: The Wind Waker