3ds Max 2012 Bible - Kelly L. Murdock [198]
Transparency is the amount of light that is allowed to pass through an object. Because this is the opposite of opacity, transparency can be defined by the opacity value. Several options enable you to control transparency, including Falloff, Amount, and Type. These options are discussed later in this chapter.
Reflection and refraction
A reflection is what you see when you look in the mirror. Shiny objects reflect their surroundings. By defining a material's reflection values, you can control how much it reflects its surroundings. A mirror, for example, reflects everything, but a rock won't reflect at all.
Reflection Dimming controls how much of the original reflection is lost as the surroundings are reflected within the scene.
Refraction is the bending of light as it moves through a transparent material. The amount of refraction that a material produces is expressed as a value called the Index of Refraction. The Index of Refraction is the amount that light bends as it goes through a transparent object. For example, a diamond bends light more than a glass of water, so it has a higher Index of Refraction value. The default Index of Refraction value is 1.0 for objects that don't bend light at all. Water has a value of 1.3, glass a value of around 1.5, and solid crystal a value of around 2.0.
Shininess and specular highlights
Shiny objects, such as polished metal or clean windows, include highlights where the lights reflect off their surfaces. These highlights are called specular highlights and are determined by the Specular settings. These settings include Specular Level, Glossiness, and Soften values.
The Specular Level is a setting for the intensity of the highlight. The Glossiness determines the size of the highlight: Higher Glossiness values result in a smaller highlight. The Soften value thins the highlight by lowering its intensity and increasing its size.
A rough material has the opposite properties of a shiny material and almost no highlights. The Roughness property sets how quickly the Diffuse color blends with the Ambient color. Cloth and fabric materials have a high Roughness value; plastic and metal Roughness values are low.
Note
Specularity is one of the most important properties that we sense to determine what kind of material the object is made from. For example, metallic objects have a specular color that is the same as their diffuse color. If the colors are different, then the objects look like plastic instead of metal. •
Other properties
Max uses several miscellaneous properties to help define standard materials, including Diffuse Level and Metalness.
The Diffuse Level property controls the brightness of the Diffuse color. Decreasing this value darkens the material without affecting the specular highlights. The Metalness property controls the metallic look of the material. Some properties are available only for certain material types.
Note
Before proceeding, you need to understand the difference between a material and a map. A material is an effect that permeates the 3D object, but most maps are 2D images (although procedural 3D maps also exist) that can be wrapped on top of the object. Materials can contain maps, and maps can be made up of several materials. In the Material Editor, materials appear as blue nodes, and maps appear as green nodes in the View pane. Usually, you can tell whether you're working with a material or a map by looking at the default name. Maps show up in the name drop-down list as Map and a number (Map #1), and materials are named a number and Default (7- Default). •
Working with the Slate Material Editor
The Material Editor is the interface with which you define, create, and apply materials. You can access the Material Editor by choosing Rendering⇒Material Editor⇒Slate Material Editor, clicking the Material Editor button on the main toolbar, or using the M keyboard shortcut.
The Material Editor comes in two flavors: regular and extra strength. The Material Editor from previous versions of Max