%0 Conference Paper
%A Gregory J Ward
%B 1991 European Rendering Workshop Conference
%D 1991
%G eng
%L LBL-30647
%T Adaptive Shadow Testing for Ray Tracing
%1 <p>Lighting Systems Group</p>
%2 LBL-30647
%X <p>We present a simple technique for improving the efficiency of ray tracing in scenes with a large number of light sources. The sources are sorted according to their potential contribution, and only those sources whose shadows are above a specified threshold are tested. The remainder are added into the result in proportion to a statistical estimate of their visibility. The algorithm requires very little storage, and produces no objectionable artifacts.</p>