This is a test I did in Houdini 11 inspired by a video I saw on emPolygonizer2.
The only light in the scene is that which is cast from the "lava".
Each frame took 15min to render, using Micropolygon PBR.
Flip simulation was a 4,5 hour.
This video refuses to compress good here on Vimeo, so download the .MOV or contact me if you want high quality :/