3ds Max 2012 Bible - Kelly L. Murdock [206]
Compared with the Blinn shader, the Specular Highlight graph looks very different. That is because it displays two highlight components that intersect at the middle. The Specular Level value still controls the height of the curve, and the Glossiness still controls the width, but the Anisotropy value changes the width of one axis relative to the other, creating elliptical highlights. The Orientation value rotates the highlight. Figure 16.6 compares the Specular Highlight graphs for the Blinn and Anisotropic shaders.
Tip
Because the Anisotropy shader can produce elliptical highlights, it is often used on surfaces with strong grooves and strands, like fabrics and stainless steel objects. •
FIGURE 16.6
The Specular Highlight graph for the Blinn and Anisotropic shaders
Figure 16.7 shows several materials with the Anisotropic shader applied. The first three images have Anisotropic values of 30, 60, and 90, and the last two images have Orientation values of 30 and 60.
FIGURE 16.7
Materials with the Anisotropic shader applied have elliptical highlights.
Multi-Layer shader
The Multi-Layer shader includes two Anisotropic highlights. Each of these highlights can have a different color. All parameters for this shader are the same as the Anisotropic shader described previously, except that there are two Specular Layers and one additional parameter: Roughness. The Roughness parameter defines how well the Diffuse color blends into the Ambient color. When Roughness is set to a value of 0, an object appears the same as with the Blinn shader, but with higher values, up to 100, the material grows darker.
Figure 16.8 shows several materials with a Multi-Layer shader applied. The first two images have two specular highlights, each with an Orientation value of 60 and Anisotropy values of 60 and 90. The third image has an increased Specular Level of 110 and a decrease in the Glossiness to 10. The fourth image has a change in the Orientation value for one of the highlights to 20, and the final image has a drop in the Anisotropy value to 10.
Tip
The Multi-Layer shader is useful to give a material a sense of surface depth. For example, it can give the illusion of a layer of shellac on wood or a layer of wax on tile. •
FIGURE 16.8
Materials with a Multi-Layer shader applied can have two crossing highlights.
Oren-Nayar-Blinn shader
The Oren-Nayar-Blinn shader is useful for creating materials for matte surfaces such as cloth and fabric. The parameters are identical to the Blinn shader, with the addition of the Diffuse Level and Roughness values.
Metal shader
The Metal shader simulates the luster of metallic surfaces. The Highlight curve has a shape that is different from that of the other shaders. It is rounder at the top and doesn't include a Soften value. It can also accept a much higher Specular Level value (up to 999) than the other shaders. Also, you cannot specify a Specular color. All other parameters are similar to those of the Blinn shader. Figure 16.9 shows several materials with the Metal shader applied. These materials differ in Specular Level values, which are (from left to right) 50, 100, 200, 400, and 800.
Note
For the Metal shader, the specular color is always the same as the material's diffuse color. •
FIGURE 16.9
A material with a Metal shader applied generates its own highlights.
Strauss shader
The Strauss shader provides another alternative for creating metal materials. This shader has only four parameters: Color, Glossiness, Metalness, and Opacity. Glossiness controls the entire highlight shape. The Metalness value makes the material appear more metal-like by affecting the primary and secondary highlights. Both of these values can range between 0 and 100.
Tip
The Strauss shader is