Hi there,
sometimes it comes to render an element of the scene separately (via "viewport selection" or by Gbuffer ID) and combine it with pre-rendered image. The problem is that when doing such thing renderer samples the boarders of particular scene object on a black CFB background which gives an annoing black fringe around it. In some cases "defringe" option in Photoshop doesnt work properly (glossy or refractive surfaces, not mentioning hair, grass or any object with high frequency of it's detail). Is it possible anyhow to swap black CFB background to a custom bitmap so it could sample fringes with it?
Cheers!