Nathan Kopp <Nat### [at] koppcom> wrote:

> For some objects, such as meshes, transformations are stored in a
> transformation matrix, leaving the base object untouched.  For a ray
> intersection, the ray must be transformed (a rather time-consuming
> calculation) into object space and then intersected with the base object.
> Then, the intersection point and normal must be transformed back into world
> space for the lighting calculation.

Hmm, if it's so expensive, why is a mesh so fast relative ot other objects
that don't need this transformation?  Is it simply because the mesh is all
triangles, which are easy to work with mathematically?

Geoff

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