Microsoft Corporation
Shadow culling

Abstract:

The present concepts relate to shadow culling when rendering a 3D computer graphics virtual world. A depth buffer may be rendered from the perspective of a camera, and the depth buffer can be used to generate a hit map, which can be used to determine which objects in the world will need shadow tests. When shadow maps are generated by rendering multiple cascades from the perspective of a light, rather than including all objects in a particular cascade into the shadow map, the pixels in the hit map corresponding to an object are checked to determine whether a shadow test will be needed for the object. If the object will not contribute to the main scene, then the object is excluded from the shadow map, thus saving GPU processing resources.