I have a question about using mental ray with global illumination and photons.
I'm rendering a shop front viewed from the outside. It's a night-time scene, with light spilling from the shop. I'm emitting a few photons from a point light inside the shop, which is working ok for me. My big worry is that the scene is becoming really inefficient, with photons spilling out into the world outside... Ultimately I want to have several shop fronts on the street so the problem may only compound itself.
I guess I'm just looking for some advice on how to manage my photons - is there a way to restrict them to the inside of the shop but allow the direct light from the point light to continue casting out onto the street?
ps. It's fine if you just point me to a relevant tutorial