CS6620 - Ray Tracing for Graphics

Project 10 - Soft Shadows and Glossy Surfaces

Duong Hoang


Intel Core i7-3610QM 2.3GHz (4 hardware cores, 8 with hyper-threading)
Nvidia GeForce GTX 660M / 2GB GDDR5 (does not matter)
Windows 8.1 Professional x64
Visual Studio 2013

Running on 8 threads, each works on a block of 8x8 pixels

Left: Uniform random sampling, 8 (shadow/glossy) samples per sub-pixel, 4 bounces, 227s
Right: Poisson disk (for shadow) and poisson sphere (for glossy), 8 poisson (shadow/glossy) samples per sub-pixel, 4 bounces, 205s
The poisson samples are rotated randomly in each sub-pixel.
It seems the poisson disk sampling removes some noise but in case of glossy reflection, 8 poisson sphere samples are too few to accurately resolve the BRDF.