Ray tracing is one of the computer graphics techniques used to render
high quality images. Unfortunately, ray tracing complex scenes can req
uire large amounts of CPU time, making the technique impractical for e
veryday use. Parallel ray tracing algorithms could potentially be used
to reduce the overall processing time. In this paper, we evaluate the
performance of three previously reported load balancing schemes for r
ay tracing on parallel processors, and propose two new load balancing
strategies. We term the new methods Local Distributed Control (LDC) an
d Global Distributed Control (CDC). Our new strategies perform signifi
cantly better than the previous methods on three standard rendering be
nchmarks. The new methods are also complementary: GDC performs well fo
r high computational complexity images, and LDC works well for low com
putational complexity images. (C) 1997 John Wiley & Sons, Inc.