Are there any 3D primitives using openGL. I know that all 3D primitives can be constructed from 2D primitives, I want a shape that is solid. For example, if I constructed a red cube from six squares, it would be hollow. And if I were to cut the tops and bottoms off with two clipping planes, i would see a hollow tunnel as a result. I want a shape that is completely coloured on the inside, and I want it such that if I were to specify different colours for each vertex, it would smoothen the colours across the shape in 3D just like for 2D primitives.

And I can't just redraw two side of the shape after the cutting planes have been placed. I'm writing a program to view 2D cross sections of a 3D model (achieved using two clipping planes, very close to each other). And I allow the user to define the clipping plane, so I don't actually know where the clipping plane is going to be, and it would be way way way too complicated to figure out based on the plane equation and all the vertices of my model, what portions have been clipped and where to draw a new polygon to cover the region. So basically, I just want an easier way to do it, and I'm hoping that there are 3D primitives cause that would make it really easy.

[This message has been edited by Rajveer (edited 04-23-2002).]