Path Tracing

Hi /porg/, Greetings from /3/.

Did you know that modern GPUs are now fast enough to do path tracing in real time?
http://www.youtube.com/watch?v=FJLy-ci-RyY

Yep, it's essentially ray tracing in real time.  Soft shadows, ambient occlusion, indirect lighting, reflection, and refraction, all in real-time.  In fact, you can even do it in a web browser.
http://madebyevan.com/webgl-path-tracing

Have a nice day /porg/.

NVidia GeForce already had photorealistic lights:
http://developer.download.nvidia.com/SDK/9.5/Samples/samples.html
This example demonstrates hardware-accelerated "ambient occlusion" using a hemisphere of shadow-mapped lights. Each light is rendered in a separate pass, and the results are summed together using a floating point accumulation buffer. The projection matrix is randomly jittered to provide anti-aliasing.

http://http.developer.nvidia.com/GPUGems/gpugems_ch17.html
A large number of lights (128 to 1024) is required for good results, but the performance of modern graphics hardware means this technique can still be faster than ray tracing. The distribution of the lights on the sphere also affects the final quality. The most obvious method is to use polar coordinates, with lights distributed at evenly spaced longitudes and latitudes, but this tends to concentrate too many samples at the poles. Instead, you should use a uniform distribution on the sphere. If the object is standing on a ground plane, a full hemisphere of lights isn't necessary—a dome or a hemisphere can be used instead.

© 2003 NVIDIA