[Pbrt-announce] Two new plugins posted to pbrt.org website

[Matt Pharr]

We've posted two new plugins to the pbrt website, both with source code as
well as short PDFs of literate programs that go through their
implementations (just like all of the stuff in the book.)  See
<http://pbrt.org/plugins.php> to download them.

The first implements an improved importance sampling method for "infinite
area lights", a.k.a. environment map light sources.  The method is easy to
implement but substantially reduces variance in rendered images by
accounting for the directional variation of brightness in the environment
map.

The second implements Wald et al's "instant global illumination" algorithm.
This technique is effectively a bidirectional path tracing method that
re-uses a small number of paths over all pixels in the image.  It does so
in a way that gives a result with no noise due to Monte Carlo variance,
instead accepting correlation in error across all pixels in the image.  It
is extremely fast, often on the order of 20% slower than just rendering an
image with direct illumination only.

-matt