+6/10/98 - problem with view culling when not looking forward. Need to
+ generate the correct matrix and work it into the calculations.
+
+6/10/98 - terrain generation - add an option to try to iteratively change
+ the error tolerance to try to generate "close" to a certain
+ number of vertices so that we can have consistent size, rendering
+ speed etc. among various terrain tiles.
+
+6/10/98 - Generate and store the transform matrix when rendering by
+ material property so we don't have to push, transform, pop
+ continually. See mesa code for gluLookAt()
+