Page 504 - Kitab3DsMax

Part IV: Materials, Cameras, and Lighting Basics

FIGURE 16.3
Increasing the Self-Illumination value reduces the shadows in an object.

FIGURE 16.4
The Opacity value sets how transparent a material is.

Specular highlights are the bright points on the surface where the light is reflected at a maximum value. The
Specular Level value determines how bright the highlight is. Its values can range from 0, where there is no
highlight, to 100, where the highlight is at a maximum. The graph to the right of the values displays the
intensity per distance for a cross section of the highlight. The Specular Level defines the height of the curve
or the value at the center of the highlight where it is the brightest. This value can be overloaded to accept
numbers greater than 100. Overloaded values create a larger, wider highlight.
The Glossiness value determines the size of the highlight. A value of 100 produces a pinpoint highlight, and
a value of 0 increases the highlight to the edges of the graph. The Soften value doesn’t affect the graph, but
it spreads the highlight across the area defined by the Glossiness value. It can range from 0 (wider) to 1
(thinner). Figure 16.5 shows a sampling of materials with specular highlights. The left image has a Specular
Level of 20 and a Glossiness of 10, the second image has the Specular Level increased to 80, the third image
has the Specular Level overloaded with a value of 150, and the last two images have the Glossiness value
increased to 50 and 80, respectively.

FIGURE 16.5
You can control specular highlights by altering brightness and size.

Phong shader
The Phong shader creates smooth surfaces like Blinn without the quality highlights, but it renders more
quickly than the Blinn shader does. The parameters for the Phong shader are identical to those for the Blinn
shader. The differences between Blinn and Phong are very subtle, but Blinn can produce highlights for
lights at low angles to the surface, and its highlights are generally softer.

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