标题: A Shading Reuse Method for Efficient Micropolygon Ray Tracing [打印本页] 作者: 晃晃 时间: 2011-12-28 09:29 标题: A Shading Reuse Method for Efficient Micropolygon Ray Tracing A Shading Reuse Method for Efficient Micropolygon Ray Tracing
Qiming Hou Kun Zhou
State Key Lab of CAD&CG, Zhejiang University
Abstract
We present a shading reuse method for micropolygon ray trac-
ing. Unlike previous shading reuse methods that require an ex-
plicit object-to-image space mapping for shading density estima-
tion or shading accuracy, our method performs shading density con-
trol and actual shading reuse in different spaces with uncorrelated
criterions. Specifically, we generate the shading points by shoot-
ing a user-controlled number of shading rays from the image space,
while the evaluated shading values are assigned to antialiasing sam-
ples through object-space nearest neighbor searches. Shading sam-
ples are generated in separate layers corresponding to first bounce
ray paths to reduce spurious reuse from very different ray paths.
This method eliminates the necessity of an explicit object-to-image
space mapping, enabling the elegant handling of ray tracing effects
such as reflection and refraction. The overhead of our shading reuse
operations is minimized by a highly parallel implementation on the
GPU. Compared to the state-of-the-art micropolygon ray tracing al-
gorithm, our method is able to reduce the required shading evalua-
tions by an order of magnitude and achieve significant performance
gains.
Keywords: micropolygon, GPU, Reyes, ray tracing
1 Introduction
Shading is typically the performance bottleneck in cinematic-
quality rendering, which is often based on the Reyes architecture
and uses micropolygons to represent high order surfaces or highly
detailed objects [Cook et al. 1987]. In order to reduce shading costs,
