[Visualpython-users] texturing untextured objects

[Jonathan B. <blo...@go...>]

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