Reflection Models

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Reflection Models

• Previous lecture
• Phong model
• Microfacet models
• Gaussian height field on surface
• Self-shadowing
• Torrance-Sparrow Model
• Today
• Multiple importance sampling
• Anisotropic reflection models

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Multiple Importance Sampling
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Multiple Importance Sampling
Reflection of a circular light source by a rough
surface
Radius
Shininess
Sampling the light source
Sampling the BRDF
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Multiple Importance Sampling

• Two sampling techniques
• Form weighted combination of samples
• The balance heuristic

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Multiple Importance Sampling
Source Veach and Guibas
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Anisotropic Reflection Model
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Anisotropic Reflection
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Anisotropic Reflection
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Quarterhorse
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Reflection from a Cylinder
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Reflection from a Cylinder
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Reflection from a Cylinder
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Reflection from a Cylinder
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Reflection from a Cylinder
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Shape of Anisotropic Highlights
Fibers tangent to the plane defined by the
halfway vector reflect light
From Lu, Koenderink, Kappers
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Shape of Anisotropic Highlights
From Lu, Koenderink, Kappers
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Kajiya-Kay Model

• Diffuse
• Specular

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Herbert
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Fiber Model
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Fiber Model
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Fiber Model
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Caustics
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Hair Appearance
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Hair Appearance
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