Efficient Divide-And-Conquer Ray Tracing using Ray Sampling
Kosuke Nabata
Kei Iwasaki
Yoshinori Dobashi
Tomoyuki Nishita
Wakayama University
Wakayama University
Hokkaido University
UEI Research
JST CREST
Hiroshima Shudo University
Abstract:
Divide-and-conquer ray tracing (DACRT) methods solve intersection
problems between large numbers of rays and primitives by
recursively subdividing the problem size until it can be easily
solved. Previous DACRT methods subdivide the intersection problem
based on the distribution of primitives only, and do not exploit
the distribution of rays, which results in a decrease of the rendering
performance especially for high resolution images with antialiasing.
We propose an efficient DACRT method that exploits the
distribution of rays by sampling the rays to construct an acceleration
data structure. To accelerate ray traversals, we have derived a
new cost metric which is used to avoid inefficient subdivision of the
intersection problem where the number of rays is not sufficiently
reduced. Our method accelerates the tracing of many types of rays
(primary rays, less coherent secondary rays, random rays for path
tracing) by a factor of up to 2 using ray sampling.
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