ИСТИНА

There are a lot of methods for rendering of shell-space geometry, represented through voxel texture, known for today. While the topic is well studied in terms of techniques for applying this geometry onto surfaces, a little attention was paid to representation of sub-pixel details of the geometry. Such details are prone to produce aliasing artifacts and reduce performance due to bad cache utilization. In this paper we solve these problems by introducing levels of detail for voxel textures within shell mapping technique. The main problem here is that less detailed levels begin to contain semi-transparent voxels on the edge of an encoded surface, which requires additional handling. For this we present a new approach for order independent transparency rendering based on depth peeling. We extend the algorithm by adding additional resolving pass which allows to fully utilize hardware z-buffering to reduce amount of overdraw. This significantly reduces cost of each subsequent peeling pass. Empirically, 3-4 of such passes is enough to produce good quality results in most cases. Another issue with shell mapping techniques is that shell geometry is constructed offline, making base surface to be static. By slightly modifying the method, we made the construction to be performed on- the-fly on GPU and be applicable for animated surfaces.