Abstract:
This paper presents a physically plausible soft-shadow algorithm that can be
executed real-time by current GPUs. The method works with a single shadow map,
requires no pre- or post-processing, and can also handle self shadowing. The
main novelty of the method is in the interpretation of the shadow map. A lexel
with depth information is considered as the geometric definition of an
elementary shadow caster. When the shadowing of a point is computed, the
algorithm decides whether these elementary casters occlude the light source area
from the shaded point, and the shadowing factors
of the elementary casters are accumulated.
Keywords:
Soft shadow, shader programming.