Autodesk 12812-051462-9011 User Guide 3 - Page 367

Index Of Refraction (out) Sets the IOR on the other side of a surface. When set to the default of zero, this control has no effect. See the section "Adjacent Refractive Materials," above. Default=0.0. Persistence Distance In conjunction with the Light Persistence color, controls the percentage of light that the volume transmits. It is the distance at which light transmission is reduced to the percentage specified by the Light Persistence RGB values. Default=1.0. If you specify an Outside Light Persistence color, that setting also uses the Persistence Distance. Ignore Normals When on, the renderer does not use normals to decide whether a light ray is entering or leaving the object. Normally, the material uses normals to decide whether a ray is entering or leaving an object. (It is entering if the normal points toward the ray, leaving if the normal points away from the ray.) This can present a problem for rendering objects whose normals are not unified. When Ignore Normals is on, the material determines whether a ray is entering or leaving the object by counting the number of times the ray has intersected the object. Default=off. Opaque Alpha When on, refracted rays that touch the environment don't generate a transparent alpha value. (This is how 3ds Max usually treats the environment.) When off, refracted rays that touch the environment render a transparent alpha value, which can help if you plan to use the rendering as part of a composite. Default=off. Phong Coefficient When greater than zero, generates Phong highlights on the material. The highlights appear in the sample slot. In general this value must be greater than 10 for highlights to be apparent. Default=0.0. Matte/Shadow/Reflection (mi) Material Material Editor > Type button > Material/Map Browser > Matte/Shadow/Reflection (mi) Note: The Matte/Shadow/Reflection (mi) material appears in the Browser only if the mental ray renderer is the currently active renderer. The Matte/Shadow/Reflection (mi) material, part of the Production Shaders on page 6017 library, is used to create "matte objects"; that is, objects that represent real-world objects in a photograph used as the scene background (also known as the plate). The material provides a wealth of options for 5622 | Chapter 19 Material Editor, Materials, and Maps