In GollyGee Blocks, most of the objects do not have texture coordinates
previously assigned, and we've got a technique which works reasonably
well and you might find useful for vpython. Starting with a list of
vertices and faces (stored by vertex index) we end up with a uv
coordinate for each vertex index on a face. In psuedocode:
For each face
Find the major axis of the face (the x, y, or z axis with the
greatest normal component)
For each vertex in the face
Drop the coordinate of the major axis from the vertex
The texture coordinates are the remaining two coordinates
normalized using the bounding box of the object
For the simple case of a cube, it puts the whole texture on the whole
face of a cube. It's not the most perfect scheme, but it was easy to
code and is fairly effective. It's also best for flat rather than
smooth shaded objects.
JB
Jonathan Blocksom
GollyGee Software, Inc. -- http://www.gollygee.com
703-437-8342
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