I have this question for so long, about using the VRay light at non-planar windows.
I mean, usually we have rectangular windows so it’s very easy to place VRay lights on them,coz a VRay light have the same rectangular shape, but how to do it when having curved corner windows (say a semi-circlular window)?
I guess it depends on if you’re using one the advanced light rigs we’ve seen examples of on this forum. If you’re just using one VRay light per window then you should be able to place the light just outside and larger than the window. This will cast area shadows in the shape of the window.
What I’d do is place three planar V-Ray lights. One in the center of the curve, and one on each side, tilted at an angle. It may not be round, but you’ll get a decent effect. I’ve not tried it though.
I was thinking about this and did a few quick tests. Since we are dealing with area lights either way looks about the same. One VRAyLight just beyond the apex of the window (plan) and larger than the opening gives a little more defined shadows than three around the curve. Since they are so similar I’d choose whichever renders faster for you.