The program in this directory, ivAddVP, is a tool that converts 
inventor files (either version 2.0 or version 2.1) into inventor 2.1 files 
that use the Vertex Property node.

If the input file contains vertex-based shapes, then the coordinates, texture
coordinates, normal vectors, and normal bindings that they use are put
into a vertex property node.  If there are multiple diffuse colors, or
if the material binding is not OVERALL, the diffuse colors will also be
put into that vertex property node.

Normals and normalBinding in the state will only be put in a vertex property 
node if the light model is PHONG.  To put them into the vertex property node 
anyway, the option -n should be specified.

If there is only one diffuse color in a material node then it will not be put
into the vertexProperty node.  This is to permit users to apply color
editors (using material nodes) to shapes that use vertex property nodes.
  
If other shapes in the scene graph do not inherit the coordinates, texture 
coordinates, normals, normal binding, and material binding, then such property 
nodes are deleted from the scene graph.  If multiple diffuse colors are in a 
material node, and no shapes (other than the vertex shapes) depend on that 
material node, then the diffuse colors will be deleted from that material node.

If VertexProperty nodes are used as nodes in the scene graph (i.e. not
as vertexProperty fields in vertex shapes, but instead using scene graph
inheritance) then these will also be deleted if remaining shapes no longer 
depend on them.

If a vertex shape node is instanced (or a node above it in the scene
graph), then it will not be converted to use a vertexProperty node, since
that could cause errors if different instances inherit different properties.
However, if the option -c is specified, then the instanced nodes will be copied,
and the copied nodes will be converted to use vertex property nodes.
This is optional because it will in some cases degrade performance by
making scene graphs too large.