Approximate Volume Rendering for Curvilinear and Unstructured Grids by Hardware-Assisted Polyhedron Projection

A hardware polygon rendering pipeline can be used with hardware compositing to volume render arbitrary unstructured grids composed of convex polyhedral cells. This technique is described, together with the global sorting necessary for back-to-front compos- iting, and the modifications that must be made to approximate cur- vilinear cells, whose faces may not be planar. © 2000 John Wiley & Sons,