Approximate soft shadow algorithm based on depth peeling and GPU
深度剥离与GPU结合的近似软影算法

To deal of umbra overestimation in some current soft shadow algorithms considering only the outer penumbra effects extended from traditional shadow mapping, a real-time approximating algorithm for plausible soft shadows based on depth peeling is proposed. The algorithm extracts the scene silhouette edges in geometry shader and generates the inner and outer penumbra primitives respectively through the silhouette edges. In the final rendering pass, the shading of each pixel is decided by referring to the shadow map and penumbra map, and plausible soft shadow effect which is more realistic than the results of previous methods is finally simulated. This algorithm runs entirely on GPU. Several experimental results show that, this algorithm generates more plausible soft shadows for relatively uncomplicated scenes than other methods and has real-time rendering speed.