Nice. Lightflow does such a great job with glass, and antialiases great. Cig looks read, too, except you need a trail of smoke. How much time did the render take?
I don’t see any caustics, however, just light transmission. Isn’t that a different thing? Most old raytracers (except annoying ones like BMRT) will automatically calculate light transmission through a transparent substance and color the light appropriately. But castics is the light actually cast from the specular surface of an object back into the environment. Hold a light up to a glass on a table and you should see that the light passes through the glass, but that there is also a pattern cast around the glass that isn’t simply from transmission, but from reflection off the glass’ specular surface. Or, another example, shine a flashlight on a mirror and light is reflected off the mirror and back at you–that is a caustic effect, right? Light going through a substance is not. Correct me if I’m wrong.
Can Lightflow calculate this light reflected off a specular suface?