Optics in threedimensional computer graphics

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Optics in three-dimensional computer graphics

• Image created by Gilles Tran, July 2006, rendered
  with the ray tracing program POV-Ray using
  radiosity (http//commons.wikimedia.org/wiki/Image
  Glasses_800_edit.png) accessed 12/01/08.

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Background

• Rendering techniques
• path tracing
• rasterization
• Three color channels
• Light sources
• Shading

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Light sources

• Ambient
• Directional
• Point source

Image credit NVIDIA The Cg Tutorial, 2003.
http//http.developer.nvidia.com/CgTutorial/cg_tut
orial_chapter05.html
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Shading

• Gouraud

Flat
Phong
Image credit http//en.wikipedia.org/wiki/Phong_s
hading and http//en.wikipedia.org/wiki/Gouraud_sh
ading
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Specular lighting
Image credit flickr photos http//www.flickr.com/
photos/18069916_at_N00/320896013/
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Bump maps and displacement maps

• Adds surface details and shadows without adding
  polygons

Image credit http//en.wikipedia.org/wiki/Bump_ma
pping
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Using dynamic bump maps to simulate interference
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Global illumination

• Diffuse interreflection

Image credit http//en.wikipedia.org/wiki/Global_
illumination
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Other special effects

• Caustics
• Lens flare
• Depth-of-field
• Volumetric lighting

GDC 2004 Light Shafts Rendering Shadows in
Participating media
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Questions?
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Reflection, refraction, and diffraction

• Natural for path tracing
• Not so with rasterization
• Three color channels give three indices of
  refraction