2008

Troubleshooting Normal Bump Maps
Because of the variety of geometry and different situations that can arise,
normal bump maps sometimes give unexpected results. Usually there is a
workaround for the problem, or more than one. This topic describes some
situations that can arise, and ways to correct them.
Parallel Projection Loses Detail
If the projection cage is set up so projected rays run parallel to part of the
high-resolution geometry, that portion of geometry can be lost in the normal
bump map.
For example, in this scene, the normal bump map is based on a high-resolution
cylinder that has indentations at the top and bottom.
6184 | Chapter 18 Rendering