The models my artists are making in maya have multiple different texture coordinates per vertex depending on what face the vertex happens to be a part of.
Originally, to fix this problem, I duplicated each vert every time it appears in a face so each vert can have its own texture coordinates / face normals. This worked out well for a while until I started working on skinned skeletal animation.
I could not seem to get skinned skeletal animation working with this duplicate vertex method. There would be serious gaps in the mesh as it animated. In order to try and fix this, I switched back to indexed drawing, where faces share verts instead of each face having its own unique copy of a vert.
This fixed my skinned animation but now I'm at a loss as how to encode the multiple texture coordinates / face normals that are associated with verts. I was hoping there might be a way to use the index buffer and an array of face normals / uvs to fix this issue. Basically, I figure I can easily add an array of normals/tex coords to each vert but I have no idea how to instruct the gpu to properly index into it.