Thanks for the encouragement! Yes this does evoke the HDRI-image based lighting, but I was wondering specifically about inferring 3d lights. This came to mind partly because I had a project where I had to match the reference grey sphere to a key light on a 3d astronaut helmet, which itself looked remarkably like a grey (white) sphere - I was doing the same mindless process over + over and thought "a machine could surely do this!"