On enhancing the speed of splatting using both object- and image-space coherence
Splatting is an object-order volume rendering algorithm that produces images of high quality, and for which several optimization techniques have been proposed. This paper presents new techniques that accelerate splatting algorithms by exploiting both object-space and image-space coherence. In particular, we propose two visibility test methods suitable for octree-based splatting. The first method, based on dynamic image-space range trees, offers an accurate occlusion test and does not trade off image quality. The second method, based on image-space quadtrees, uses an approximate occlusion test that is faster than the first algorithm. Although the approximate visibility test may produce visual artifacts in rendering, the introduced error is usually not found very often. Tests with several datasets of useful sizes and complexities showed considerable speedups with respect to the splatting algorithm enhanced with octree only. Considering that they are very easy to implement, and need little additional memory, our techniques will be used as very effective splatting methods. (C) 2000 Academic Press.
splatting coherence optimization visibility octree range tree quadtree