Conference 5–9 August 2012
Exhibition 7–9 August 2012
Los Angeles Convention Center

Brigade: Real-time Photorealistic Rendering With GPU Path Tracing

Los Angeles Convention Center, West Hall B

In pursuit of real-time photorealism, today’s rasterized games require an ever-increasing amount of tricks and combination of hacks to achieve effects like soft shadows, ambient occlusion, non-planar reflections, and indirect lighting with diffuse interreflection. Adding new effects without breaking existing ones makes the code extremely complex and difficult to maintain. Path tracing handles all these effects with a simple and elegant, physically based light-transport algorithm, which is suitable for parallelization and can render a pristine photorealistic image quality using arbitrary BRDFs, which is impossible to achieve with rasterization. Until recently, path tracing has been considered too computationally expensive for creating special effects in films and animations, let alone for real-time graphics applications such as games. However, due to recent advancements in graphics hardware, including increased programmability and parallelism, the GPU is now able to accelerate path tracing by an order of magnitude compared to the CPU. In some “ideal” scenarios (scenes with open environments lit by a skylight or large light sources, with few indirect lights and simple materials), GPU-accelerated path tracing is now fast enough to converge at real-time frame rates, making it suitable for displaying dynamic scenes and enabling photorealistic games, architectural walkthroughs, and simulations. The real-time path-traced images convey an unrivaled sense of realism with physically accurate reflections, refractions, soft shadows, caustics, and diffuse color bleeding.

Sam Lapere
Jeroen van Schijndel
Jules Urbach
Rob Wyatt
Malcolm Taylor
OTOY, Inc.