Integration of Realtime Ray Tracing Into Interactive Virtual Reality Systems

Hilko HoffmannDmitri RubinsteinAlexander LöfflerMichael Repplinger, and Philipp Slusallek 
Proceedings of the 2nd Sino-German Workshop Virtual Reality & Augmented Reality in Industry
Shanghai, China, April 16-17, 2009 



Current processors provide high performance through parallelism by integrating more and more computational cores on a single chip instead of increasing the clock rate. This is true for both the CPU (multi-core of up to 8 cores) and even more so for the GPU (many-core of up to 240 cores). GPUs are still being programmed in vendor specific languages (like Nvidia's CUDA) but cross-vendor initiatives like OpenCL will allow for providing performance on a standard desktop PC that was previously only possible on supercomputers. With is upcoming Larrabee processor, Intel goes one step further and tries to combine the concepts and advantages of multi-core CPUs with that of many-core GPUs. It moves the entire rendering process into software providing more flexibility to realtime graphics applications like games or visualization applications.

In this paper we present a highly parallel System consisting of the completely new Realtime Ray Tracing engine "RTfact" and the Realtime Scene Graph "RTSG" that allow making good use of modern parallel hardware. RTfact accelerates rendering via ray tracing to the point where it can be used for interactive Virtual reality applications, while RTSG allows for flexible and high-level descriptions of 3D environments on the basis of the X3D standard that enable the description of 3D objects and their behavior. RTSG is thus the interface between Virtual Reality systems and a number of different rendering modules that includes ray tracing as well as fast rasterization via the OGRE library. RTSG currently is the fastest X3D browser that optimally supports construction and design decisions through high image quality, exceptional visual realism, as well as the high degree of detail in scenes.