Interview - Intel will soon be extending its product portfolio into visual computing. And while Nvidia isn’t publicly admitting that Intel is an increasing threat to the company, we know that Intel isn’t aiming for second place. While Larrabee is one of the firm’s key hardware products, Intel is busy developing lots of related technologies in the background as well - including ray-tracing engines. We had a chance to talk to Intel’s Daniel Pohl, a young German engineer who first got our attention when he rewrote the rasterization engines of Quake III Arena and Quake IV into full-blown ray tracing engines. Back then, Daniel used OpenRT API. Today, he is developing API currently known as IntelRT and gave TG Daily editor Theo Valich a fascinating look into his work.
In our recent interview with EPIC founder and Unreal creator Tim Sweeney, we learned about the future integration of CPU and GPU instructions, indicating that we will see code that executes on graphics chips or the CPU, whichever proves to be the faster technology. It is a trend we have been seeing for a while especially on the GPU side and floating point accelerators. On the other hand, the x86 CPU seems to be moving towards GPU capability. Nvidia’s CUDA has the lead in general purpose GPU (GPGPU) computing today and is providing monstrous processing horsepower through the graphics chip. Intel recently announced AVX, 256-bit extensions that will join its processors with the 2010 Sandy Bridge 32nm processor generation and try to do the trick from the CPU side.
AMD is a somewhat silent player in this arena, but the company is actually deeply involved in GPGPU applications. Companies like British Petrol (BP) have been using FireStream cards based on X1900XTX chips for GPGPU purposes ever since ATI’s GPGPU platform was launched back in September of 2006.
But the development of GPUs and CPUs does not stop here: Upcoming cGPU products (Larrabee) are geared towards the task of solving computational problems such as ray tracing. In fact, Intel is developing a ray tracer called IntelRT. We sat down with Daniel Pohl, research scientist with Intel, to learn more about this particular project and how Intel plans to change the game of graphics.
TG Daily: What prompted you to use ray tracing in games and replace the common rasterization process?
Daniel Pohl: It all started in 2004 when I was studying at Erlangen University in Germany. I listened to a talk from professor Slusallek, who was researching real-time ray tracing. I got really excited, because I initially had thought that ray tracing could not be used for anything more than movie production. Slusallek showed some real-time demonstrations and I wondered why someone would not not use this technology in games. I contacted professor Slusallek and rewrote the Quake III engine based on ray trace graphics (based on OpenRT).
TG Daily: After Quake III and some media reports, you rewrote Quake IV using ray tracing as well and somehow ended up at Intel in California. What are you working on these days?
Daniel Pohl: I am a research scientist in the ray tracing group. We explore real-time ray tracing, for example the dynamics of how to improve performance, improve scalability and, most importantly, how to improve the image quality. This, for example, includes Adaptive SuperSampling (AntiAliasing).
TG Daily: When we look at the differences between ray tracing and conventional rasterization, it appears that ray tracing can be used for much more than displaying motion.
Daniel Pohl: You are correct. Once you accelerate ray tracing to a decent speed, you can use it for collision detection, or use it for AI [Artificial Intelligence –ed] to determine certain assets. For example, you could use camouflage to test the AI: You can determine the visibility of something when it is hiding behind different objects such as trees or one or more other solid objects. Ray tracing is not all about rendering. It is about how much more you can do using a single technique.
TG Daily: That puts in-game physics into a whole different perspective.
Daniel Pohl: Yes, this is a very good thing because we can have everything game-related in a single structure. We don't need separate structures for collisions, a separate one for graphics, a separate one for physics, a separate for AI and so on. If you want, you can use a highly optimized ray tracing structure to test everything. If you don't like [the results], you can use an additional [structure], but you are not forced into using it.
Read on the next page: How scalable is ray tracing?