Recently I’ve been having some fun with Blender and Luxrender
Here are 18 scenes, in all of them there is ONE ray of light coming in (from right) from an IES area lamp, which is then made to reflect & refract up to 300 bounces in some cases. Most of these are rendered in just two minutes and some in just 30 seconds, the idea was to just get the light path visible - a couple of pictures have got a little more render time though
It’s really interesting to try out different kind of setups and try to get the light trapped, a small tweak can have a big effect on some of the scenes.
Some of these are pretty incredible if you think what the light has to go through, poor light
Try to follow the path of the ray if you can!
Click the thumbnail to show the picture.