Transcript Kein Folientitel

Shading Languages
By Markus Kummerer
State of the Art Shading
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Overview
 RenderMan Interface
 Shape vs. Shading
 Types of Shaders
 Shading Language
 Examples
 Interactive Multi-Pass Shading
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RenderMan Interface
 Powerful set of primitive surface types
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Quadric surfaces
Polygons
Parametric surfaces
 Hierarchical modeling, geometry
 Constructive solid geometry
 Camera model
 Generalized shading model
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Shape vs. Shading
 Shape
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Geometric configuration of objects
 Shading
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Calculates the appearance of an object in a
scene under a set of light sources
Result defined by
 Colors
of the surface and the light source(s)
 Position and orientation of the surface relative to
the light
 Roughness of the surface
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Shading Pipeline
 Three basic parts of the shading process
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Emission at the light source
Interaction of the light with the surface
Atmospheric effects between the surface
and the viewpoint
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Types of Shaders
 RenderMan Interface supports
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Light source shaders
Surface shaders
Volume shaders
Transformation shaders
Displacement shaders
Imager shaders
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Light Source Shader
 Calculates the intensity and color of light
sent by the light source to a point on a
surface
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Surface Shader
 Determines the color of light reflecting from
a point on a surface in a particular direction
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Volume Shader
 Generalizes the idea of atmosphere
affecting light passing through space
between a surface and the eye
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Shading Language
 Orthogonal definition
 Rendering environment
 Special data types
 Uniform and varying variables
 Integration constructs
 Filtered map access
 Function library
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Examples
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Example: Surface Shader
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Example: Surface Shader
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Example: Displacement Shader
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Interactive Programmable Shading
 OpenGL acts as an assembly language for
shader execution
 Compiler is introduced between the
application and the graphics library
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Interactive Programmable Shading
 Results
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Conclusion
 Shading in software
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Common technique for production animation
Offers generalized shading models
Provides a highly flexible approach
But is not interactive...
 Shading in hardware is needed for
interactivity
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Hope you are delighted, too
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