V-Ray RT and dome lights

[Mark Thompson]

I've noticed, in a demo, that V-Ray RT supports dome lights for image-based lighting, which is great for quick visualization. But the dome seems to be rendered in the RT ActiveShade viewport even when "invisible" is checked (and when there is no environment map). Does this mean it's impossible to use an image-based dome light in the RT viewport while keeping a plain (ex., black or white) background? If so, that really limits the usefulness of V-Ray RT for IBL.

Can someone confirm if this is a limitation of that V-Ray RT demo of it it's the same in the final version?

Thanks in advance,

M.T.

[Mark Thompson]

Can someone (from ChaosGroup or just a user with the full version of V-Ray RT) confirm or deny this?

Just create a scene with a couple of objects, add a dome light, assign an HDR image to the dome for lighting, and see if you can make the light / shadows work correctly in the V-Ray RT viewport without the dome image appearing (i.e., with a plain black or white background). From what I saw, the "invisible light" option works fine in the main renderer but not with V-Ray RT, and turning off "renderable" in the dome light's options turns off illumination.

[urbanite]

I think "invisible" is unsupported and you should have this information displayed on screen, of course if you have not switched the warnings off.

[Mark Thompson]

It just said "warning: invisible is a non-physical property" or something like that, I'm pretty sure it didn't say "unsupported".

Anyway, it doesn't have to be that option. I just want to know if there's a way to have the actual scene background display, instead of the dome light's image (while still using the dome light to light the scene). If it's impossible to turn it off, that makes V-Ray RT's dome light support kind of useless for most situations.

[urbanite]

Ok, I must appologise for my previous post. I have checked this and seems to work fine. I have got the massage that it is non-physical property but the lighting and shadows are the same. I rember having similar problem in the past but it seems that with vray 2.1 it is working as expected, not sure about demo version.

[Mark Thompson]

The problem is not related to any shadows. As described in the first message, the problem is that, when we turn on "invisible", the dome light image remains visible in the V-Ray RT activeshade window. In other words, although our environment background is plain white and the dome light is set to "invisible", the background of the rendered image is the dome light image, not the white background. This means we cannot use image-based lighting with V-Ray RT (since we don't want the photo to be visible in the background).