A quad is basically a 3d square, 4 vertices, 2 triangles which you create in code using addvertex etc... It's very similar to a 3dsprite but any camera alignment has to be done yourself.
The main usage, for me at least, would be for a 3d GUI or single surface particle system.
Stevie
The main usage, for me at least, would be for a 3d GUI or single surface particle system.
Stevie