2008

type of mapping system is used with reflection, refraction, and environment
maps.
There are four types of environment coordinates:
■ Spherical
■ Cylindrical
■ Shrink-Wrap
■ Screen
The first three are the same as those used by the
UVW Map modifier on page
1849 . If you imagine a sphere, infinite in size, surrounding your scene and
mapped with spherical mapping coordinates, you can visualize the effect you
get with spherical environment mapping. Shrink-wrap wraps the map around
a giant sphere, leaving only one singularity. Cylindrical is like a giant cylinder.
The Screen system maps the image directly to the view, with no distortion.
It's similar to planar, in that it's like a giant backdrop hung in the scene. Unlike
the other environment mapping methods, Screen is locked to the view. When
you move the camera, the map moves with it. Therefore, you can only use it
for still renderings, or animations in which the camera doesn't move.
To use a bitmap with any environmental mapping system other than Screen,
you need a high-resolution map because of the size of the virtual sphere, or
cylinder.
An environment map is not assigned in the Material Editor, because it's not
applied to the geometry of an object, but rather to the scene itself.
Environment maps appear in the background, as seen from the camera or
perspective view.
When you assign a map to the environment, it's the same as if you'd assigned
a mapped material to an object in your scene. To edit or adjust the assigned
map, you need to place it in one of the sample slots in the Material Editor.
You can do that in one of two ways:
■ Click the Get Material button in the Material Editor, and then get the map
from the scene.
■ Put the map from the Environment dialog to one of the sample slots in
the Material Editor. You can do this by dragging and dropping from the
Environment dialog map button to the sample slot.
Glossary | 7769