This is really very simple
You are right, not difficult once you know how. Thanks so much for good instructions! This opens lots of possibilities. Tested to see whether it was as easy as you said. And yes, making a model and editing the .mtl did not take many minutes - even if the rendering was a pain, as you warned. Thankfully glow without the path at the next best rendering level is still pretty nice - and much faster. Testing your instructions compared with model with built in lightsource - at quality 2,3,4:
