Sub-geometry Shadow Mapping Based on Normal Detection

This paper presented a method for sub-pixel hard shadows rendering in real-time. The method focused on addressing the aliasing artifacts due to the limited resolution of shadow maps. Inspired by the fact that the reconstruction of the depth value of an occluding point is according to the geometry information stored in the texel, we built a sub-geometry shadow map (SGSM) to detect multiple triangles in one texel based on normal detection, and improved it by a shared normal strategy (iSGSM). Experiments show that our approach is an effective shadow map based method, which reduces the jagged shadow boundaries greatly and produces high quality shadows.