Retrieving Coords of Point After Many Transformation

I have a work task that involves modeling the human spine. It’s developed to the point where the spine model is in place, I can select a vertebra, and rotate around it’s centroid. As it rotates, all vertebra above it rotate with it. Next I need to retrieve the coordinates of the centroid of the vertebra at the top of the spine. We want to see how far that point has moved as a function of all the vertebra rotations below it. I am working in fixed function OpenGL.

Appreciate any good suggestions.

Thanks

[QUOTE=Carmine;1248851]I have a work task that involves modeling the human spine. It’s developed to the point where the spine model is in place, I can select a vertebra, and rotate around it’s centroid. As it rotates, all vertebra above it rotate with it. Next I need to retrieve the coordinates of the centroid of the vertebra at the top of the spine. We want to see how far that point has moved as a function of all the vertebra rotations below it. I am working in fixed function OpenGL.

Appreciate any good suggestions.

Thanks[/QUOTE]

Just solved the problem by retrieving a carefully set up model transformation matrix.