Rendering the Enforcer - ZBrush Creature Design: Creating Dynamic Concept Imagery for Film and Games - page 686

MatCap stands for “material capture,” just as LightCap stands for “light capture.” The idea behind both tech-
nologies is very similar. Like LightCaps, MatCap materials use a texture to determine how the material is
lit and shaded. The specular highlights, diffuse reflections, and other material qualities are “baked” into a
texture and ZBrush references this texture when it renders the image.
There are two key things to watch out for when using MatCap materials:
• Since specular highlights and reflections are baked into the material, it is possible to render a sur-
face in which the highlights are not aligned correctly with the direction of the lights in the com-
position. Figure 10-36 shows an example where the highlights on the sphere and the torus are not
properly aligned with each other and neither highlight is aligned with the shadow-casting light
when the scene is rendered with BPR.
• The LightCap editor can be used to create MatCap materials. This is a really great way to design
MatCaps. All you need to do is select a MatCap material from the upper half of the Material lib-
rary and then open up the LightCap editor and make some changes. As soon as you make any
changes to the LightCap editor, the lighting is instantly baked into the selected MatCap material.
This is great, except that it means that it is very easy to accidentally destroy the current material
and Undo is not going to reverse the changes (see Figure 10-37 ) .
The first problem is fairly easy to solve. In the Modifiers for MatCap materials there is an Orientation A
slider, which allows you to rotate the MatCap texture so that you can align the highlights with the lights in
the scene (see Figure 10-38 ) .
Figure 10-36: The highlights of the rendered model are not aligned with the shadows.