Graphics Programs Reference
In-Depth Information
Rendering Refractions
Refractions are also a raytraced-only ability. Refractions require that an object be semi-
transparent so that you can see through it to the object (or objects) behind it that is being
refracted. To control refractions, use the shader.
To enable refractions, select the appropriate shader in the Hypershade, and open the
Attribute Editor. In the Raytrace Options section, click the Refractions check box. Now
you need to set a refractive index for the shader and a refraction limit, similar to the
reflection limit.
The refractive index must be greater or less than 1 to cause a refraction. Typically, a
number within 0.2 of 1 is perfect for most refraction effects. The first image in Figure 11.13
is raytraced with a refractive index of 1.2 on the wine bottle and glasses; the second image
has a refractive index of 0.8 on both bottle and glasses.
You can specify whether an object is visible in a refracting object by clicking or
clearing the Visible in Refractions check box in the Render Stats section of the object's
Attribute Editor.
Figure 11.13
(left) Refractive
index of 1.2; (right)
Refractive index
of 0.8
Using Cameras
Cameras capture all the animation fun in the scene. In theory, Maya's cameras work the
same way as real cameras. The more you know about photography, the easier these con-
cepts are to understand.
The term c
amera
, in essence, refers to the perspective view. You can have as many
cameras in the scene as you want, but it's wise to have a camera you're planning to render
with placed to frame the shot and another camera acting as the perspective work view so
you can move around your scene as you work. The original persp panel fits that latter role
well, although it can be used as a render camera just as easily.
You can also render any of your work windows to test render orthogonal views of your
model the same way you render a perspective view.
