Shadow Algorithms Data Miner

116 4. Soft Shadows

inner and outer penumbrae. e above approaches can be slower and require

some knowledge or assumption of object relationships, which can get quite

confusing with more complex scenes.

Among the above approaches, PCSS [173] is the cleanest and most oen used

approach. In fact, there are optimizations to this approach that combine PCSS

with variance or convolution shadow maps (Section 2.3.6). ey are appropriate

extensions because of the potentially large lter sizes needed to achieve the so

shadows, which can signicantly slow down the basic percentage-closer approach.

Lauritzen [336] creates several preltered layers and stores