GPU rendering of dome lights with UV mapped textures

[simon_lundberg]

If you apply a texture to a dome light with what 3ds Max calls "explicit map channel" (i.e, UV coordinates), V-Ray CPU just grabs the top-left coordinates of the image. That seems sort of reasonable; dome lights don't actually have any UV coordinates. But V-Ray GPU however uses some other projection method and I cannot reproduce it in V-Ray CPU.

The projection used by V-Ray GPU is similar to a mirror ball projection, but not exactly the same. I want to recreate exactly the projection used by V-Ray GPU in V-Ray CPU, but I have not been able to do so.

I have attached a scene and some renders demonstrating the issue.

The behaviour is the same in V-Ray 6 and 7.

Any suggestions?

[simon_lundberg]

Here are the CPU renders of the same scene.

[hermit.crab]

I guess V-Ray GPU defaults to some internal UVs. You could try activating the Finite Dome together with the Mirrored Ball projection. I played around with the VRayDome's radius, projection height, and a bit of transformation and managed to make something similar. Attaching the scene.

[simon_lundberg]

Presumably it means that the exact settings (radius and projection height) become scene dependent though, so it might be difficult to make it work in my case. Still, seems worth trying. Thanks!