Per-Pixel Displacement Mapping Using Cone Tracing

The technique of cone tracing, used for rendering v ery detailed surface in real-time, is certainly among the best techniques at the prese nt time. But unfortunately, in its two versions, conservative and relaxed, this technique suffers fr om a heavy pre-processing having a quadratic complexity. Moreover, the processing of non-square textures remains a problem. In this article we introduce a new linear complexity algorithm for gen erating relaxed cone maps. Additionally, we propose to use the Height Distributional Distance T ransform HDDT for creating conservative cone maps. The HDDT is a linear algorithm used in t errain rendering. We also introduce a new method for supporting non-square textures using an elliptical rectification. Finally, we suggest using the cones' radius instead of their ratio. Thi s eliminates the constraint limiting the cones' apex angle to π/4 which significantly improves the performance of the cone tracing technique.