I’ve spent the past month or so trying to wrap my head around photon mapping. In theory it’s pretty simple, but in practice there are a heck of a lot of settings to get right. Too far one way and you’ve got blotchy pools or light… too far the other way and you’ve got razor-sharp caustics and rendering times that are best expressed in scientific notation.

Here are a few of the cooler tests. I’d put up a tutorial, but there’s already a lot of really top-notch ones out there. (Click for high-resolution versions.)