A little over three years ago I read the paper "Ray Differentials and Multiresolution Geometry Caching for Distribution Ray Tracing in Complex Scenes" by Christensen et al.

I was inspired.

I was (and am) a huge fan of the Reyes rendering architecture, but the industry was clearly moving away from Reyes towards global illumination ray tracing. I didn't see that as a bad thing—ray tracing clearly has a lot of benefits over Reyes. But Reyes has a lot of cool properties that are lost in that move to ray tracing.

Reading that paper by Christensen et al. gave me the idea that it might be possible to merge both worlds: ray tracing and on-the-fly micropolygons. And I was curious how a renderer built on that paper's algorithms would perform when used as the basis for a path tracer. So I set out to write a simple proof-of-concept, just to see if I could make it work. The idea seemed kind of crazy, so I decided to call the renderer "Psychopath", for "Psychotic Path Tracer". I was just tinkering for fun, after all.

Three years later and I'm still working on it. It's been long enough (and addictive enough) that I'm pretty sure I'm not going to stop any time soon. So I'm making a website for it.

I have pie-in-the-sky hopes that I'll be able to turn it into a genuinely useful 3d renderer. But who knows. Ultimately, Psychopath is a platform for me to experiment with weird/crazy rendering ideas.

At this point there is very little (if any) of the Christensen et al. paper left in Psychopath. But I nevertheless owe the authors a debt of gratitude for the inspiration. It's a really cool paper.