None that I've been able to find yet. And a very, very good question. Unlike HDRI, where you usually attach the image to a sky or sphere on which the texture is seen, IBL is just a light. So, where is the main light source in the IBL image? Does it coincide with the light's direction? Would be nice to know this. Let's hope someone has an answer.

C makes it easy to shoot yourself in the foot. C++ makes it harder, but when you do, you blow your whole leg off.

 -- Bjarne Stroustrup

Contact Me | Kuroyume's DevelopmentZone