PC Perspective has taken a look at the technology behind the CausticOne, a ray tracing processing unit (RTPU) card that will be released in Q1 2010. The company was found by three ex-Apple engineers and promises to significantly increase the speed at which a computer can generate ray traced graphics.
The RTPU (ray tracing processing unit) that Caustic has developed handles only the ray tracing portion of the calculations required for a complete rendering system. When a ray is created in the shader software the entire process of that ray bouncing around the scene and activating shaders is handled solely by the Caustic card. The magic in the design is that they claim to have figured out a software and hardware combination that allows them to compute tremendous numbers of rays with much higher bounce allowances than modern ray tracing systems while maintaining real-time efficiency. The CausticGL software then passes the resulting shaders that need to be run on various pixels to the GPU in such a way that it can efficiently run the code on its architecture. That means what the Caustic hardware is doing is essentially taking what would normally be random shader results from a ray tracing algorithm and compiling the data in a format that the GPU is used to seeing – code that can run with high memory locality. This means the GPU can do what the GPU does very well in terms of mass shading power while leaving the work that it is less efficient at to the Caustic software and hardware design.