I am motivated by interesting work, rather than the financial reward it provides, and I find your project to be particularly interesting.
I have 5 years experience with C++, and 3 years experience with GPGPU programming in both OpenCL and CUDA. I have written numerous high-performance CUDA codes, and for my final university thesis I wrote a computational CUDA code with provided a 50x performance improvement over existing code.
Additionally, I am extremely interested in graphics programming, and understand the graphics rendering pipeline intricately -- from the hardware level to the graphics APIs. I have also developed a physics engine to render particles using CUDA and OpenGL.
I also document code thoroughly, both within the source code when required, as well as creating external documentation so that any future developers working on the problem can easily understand and use the software I have developed.
I am confident that I can produce I high quality solution to your problem.
NOTE: As I am not driven by the financial reward, I am flexible on the rate, please contact me if you like my proposal but would like to negotiate the rate.