Can't exclude lights in environmentFog

[Undersky]

I'm having trouble with environment fog acting up.

My scene is down in a mine and I have a machine that's backlit with a vray sphere light. I also have a sphere that I've filled with environmentFog (and a vrayMtl with no opacity for the sphere itself). So I want the mine shaft behind the machine to have some bluish fog behind the machine.

Now, I want to control which lights that are used in the environmentFog, but nothing I do seems to have any effect. First of all, I get a visible shape of a vray rectangle light in the environmentFog. I've had this earlier in 3ds max and solved it by upping the subdivs for the fog. However, that doesn't help here. So I thought I'd try and exclude the light from the fog, but I can't get it to work.

I've even tried excluding all of the lights (Relationship editors / light-linking), but it has no effect whatsoever. And it doesn't matter if I set Light Mode to "Override shape lights" or any of the other modes, nothing changes. It uses all of the lights whatever I do, even if I set it to "No lights".

Maya 2014, V-Ray 2.3.

[ivaylo.ivanov]

Here is simple example:

fog.zip

If you have problems on the actual scene you can try to simplify it and send it to the support.

[Undersky]

Thanks!

It halfway works now... I can at least control if the lights contribute to the environment fog or not.. I unlinked the lights from the environment fog node, not the object itself. So now at least stuff happens when I change light mode =)

However, I still get the shape of the light in the render, even though there's only one light (a spherelight) that's linked to the fog object... Guess I have to send the simplified file to the support.

[Svetlozar Draganov]

Yes - it would be easy for us to investigate what's going on directly on your file, instead of trying to first reproduce the same thing here.
Send you scene to vraymaya@chaosgroup.com with a link to this thread as well.

[ivaylo.ivanov]

The "Use shape lights" option has one strange behaviour currently. The fog uses the light links not of the shape that it was assigned to, but the shape that was intersected. So if you have another object inside the fog that receives lighting from other lights, you can get weird result. Will see if this can be fixed in VRay 3.0. If you have such setup, use the "Override shape lights" option and assign the lights to the environment fog.