Hardware-assisted visibility ordering for point-based and volume rendering

This paper presents a method to accelerate algorithms that need a correct and complete visibility ordering of their data for rendering. The technique works by first pre-sorting primitives using three lists - one for each axis, and then combining them using graphics hardware, by either clipping the projected primitives while rendering, according to the current list being processed, or by rendering each list to a texture and merging the textures in the end. We show that our algorithm works by applying it to the splatting technique using several types of rendering, including classic splatting and volume rendering.