Cook-Torrance Shading
 
 
 

DEPRECATED. This shader is unsupported, but it may still get installed with Softimage to provide compatibility with older scenes that use it. It is recommended that you replace unsupported shaders in your scenes with equivalent shaders from the current Softimage shader library.

| Render Tree Usage

Shader Type: Illumination (surface)

Output: Color (RGB) value

Creates Cook-Torrance--type illumination. It controls the ambient, diffuse, and specular RGB colors, as well as roughness and Index of Refraction (on three wavelengths). Cook-Torrance lighting has an off-specular peak and a color shift with angles.

Name

The shader's name. Enter any name you like, or leave the default.

Diffuse

Diffuse

Defines the surface color in the illuminated area of the object. This value is blended with the object's Ambient value.

Ambient

Determines how strongly the global ambiance (indirect illumination) will affect the object.

Specular

Specular

Defines the specular color of the object.

Roughness

Controls the width of the specular highlight.

Refraction

Controls the bending of light through a transparent material. Defines the index of refraction, which varies according to the nature of the material. (The refractive index of water is roughly 1.33, and that of vodka is about 1.36.)

Default = 1 (the refractive index of air), which allows light rays to pass through a transparent material without distortion.

Global Illumination / Caustics / Final Gathering

Radiance

Used to control the color and intensity (strength) of the GI/FG/Caustic effect over the object's surface. Also, you can texture this parameter in order to reveal a GI/FG/Caustic effect on a given location on the object.

Render Tree Usage

This illumination shader can be used almost anywhere in a render tree, just like a surface shader. The illumination nodes are faster and take less memory since they don't calculate any reflections, refractions, or transparencies. You can use any number or combination of illumination and surface shaders to control various parts of your effect. Illumination shaders are often mixed (as the Base Color using a mixer shader) with textures to add realism to them. Also, you can use textures to control color inputs (such as Diffuse or Ambient) or scalar output nodes (such as gradients or fractals) to control refraction or translucency.