ABSTRACT
Shadow Map Silhouette Revectorization (SMSR) is a two-pass filtering technique inspired by MLAA that aims to improve the visual quality of a projected shadow map by concealing the perspective aliasing with an additional umbra surface. In most cases under-sampled areas result in a higher shadow silhouette edge quality. The SMSR technique consists of two fullscreen passes and requires access to the depth buffer, shadow map, lighting buffer, view matrix, light matrix, and inverse of the light matrix. SMSR is only concerned with the exterior discontinuity of the shadow silhouette edge. When an exterior discontinuity is detected, the direction from the current fragment sample toward the discontinuity is encoded into one of the output channels (used in the second pass to determine discontinuity orientation). SMSR doesn’t come without its drawbacks, which are categorized into special cases, absence of data, and mangled silhouette shape.
