Dielectric Shader

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The Dielectric Physical Phenomenon Shader is used by Mental Ray. A shader is a set of algorithms that inform the ray trace engine of specific behavior of a material or surface. The Dielectric shader is used for materials such as liquid or glass with a high index of refraction by modeling the behavior of rays passing between materials with differing refractive indices, as well as attenuation of the ray as it passes through a material.

[edit] Dielectric Shader

The shader uses Fresnel equations to simulate reflectance and transmittance of light passing through the dielectric interface, as well as using Snell's law to determine the angle of refraction. In addition Beer's law is used to determine absorption of rays passing through dielectric materials.

Two types of dielectric interfaces are supported:

• dielectric-air between a dielectric material and air.
• dielectric-dielectric between two dielectric materials.

[edit] Gallery

Frosted Glass: composed of Dielectric and Spekle bump mapping.

Red, Green and Blue rings demonstrating Fresnel reflections.

Solide Glass letters with IOR of 1.333. (different IOR demonstration).

Two solid dielectric objects overlapping to show the refracting effect.