We can ray trace too, says Nvidia

It's get real time for GPU

HIGH-END GAMING PCs will soon have raw power to handle photo-realistic graphics fluidly and in real time. Even Nvidia powered ones.

Intel recently boasted that its promised Larrabee architecture could perform real-time ray tracing. Nvidia says it is already possible under existing technology designs.

Nvidia demonstrated at Siggraph in Los Angeles that traditional GPUs could still handle real-time ray tracing using CUDA.

What we are witnessing is ‘the world's first fully interactive GPU-based ray tracer’, said Nvidia at the show. They achieved it using a Quadro Plex 2100 D4 Visual Computing System (VCS) with four Quadro GPUs, each equipped with a gigabyte of memory.

Nvidia says, ‘the ray tracer shows linear scaling rendering of a highly complex, two-million polygon, anti-aliased automotive styling application.’ True, perhaps, but it’s very much a techie’s demo, at the moment, and we’re a long way from seeing a mainstream game using this technology. And a lot can happen in the interim.

Still, fair play to Nvidia, which claims the polished car demo runs at 30fps at 1,920 x 1,080. It also included ‘an image-based lighting paint shader, ray traced shadows, and reflections and refractions’ at three bounces.

Nvidia also demonstrated the demo running at 2,560 x 1,600 though didn't disclose frame rates at that resolution.

Ray tracing is used to generate images by tracing the rays or paths of light as they bounce through and around the objects in a scene. When done right, it can produce photorealistic imagery because shadows are reproduced correctly. But the algorithms needed are complex and processor intensive.

Intel's Daniel Pohl has demo-ed customised versions of Quake 3 and Quake 4 running on Intel hardware that use ray tracing with impressive results. ATI has ray traced demos running on Radeon HD 4800 series hardware at their Cinema 2.0 event.

Now Nvidia is up to speed. Or is it?