Shadow Algorithms Data Miner

70 2. Hard Shadows

An interesting class of algorithms use GPU projection textures [426, 421, 438]

to render shadows. Nguyen [426] renders projected polygons to a GPU texture

and applies this texture onto the receivers by computing its projective texture co-

ordinates on the y. Two papers [421, 438] discuss the use of shadow depth map

results to project shadow textures onto receivers. e shadows are generated as a

result of multipass rendering of the shadow textures with the receivers. Although

these techniques are quite fast, the main limitations are that an object cannot self-

shadow and can only be an occluder or a receiver, not both. Further,