Vray - What Render Element should I use to isolate illumination from a VRayLightMt?l

#1

Hi there,

I am fairly new to VRay and I am trying to set up my animation scene for rendering with a few render elements, nothing too complicated. The scene is an interior illuminated with a Dome light, a VRay rectangle light and two stained glass windows that have a VRay Light Material applied to them. So, the elements that I am using (well, the ones relevant to the lighting of the scene) are GI, a Light Select for the dome light, another Light Select for the Rectangle Light, and Self Illumination for the stained glass windows. Everything seems correct to this point. The thing is, both stained glass windows have the Direct Illumination checker (under the Direct Illumination tab on the attributes of the Light Material) set as active, so the material emits light. And I don’t know how to extract that light contribution to a separate render pass… The composite of my render passes doesn’t look like the RGB pass, it’s missing just that bit. Could anyone give me some hints on how to do it or point me to any tutorial? I have been looking for a while with no luck. I’m attaching two pics so you can see what I mean. Now that I see both images side by side, there might be something else I’m missing but I can’t be sure…

Any help would be greatly appreciated

Cheers!


RGB


COMPO

#2

As you say, you’re missing the direct lighting from the Windows that are emiters.
One way to bring them back is to calculate a lighting pass then substract all your light select element from it (dome, area,etc…) then you will only have the windows.
Add that remaining pass you just create to your light select elements and you should be good to go.

Cheers

#3

Fantastic! Very clever, that seems to be working, thank you so much! Now if you (or anyone) could help me with something else you would just make my day :bounce:

The things is the character’s hair (or straw or whatever it is) doesn’t look the same on the RGB image and the composite, it looks faded and dull on the composite. As it looks fine on the RGB layer I’m guessing it’s an issue of the render elements as well. It has just a VRay material with a map on the diffuse slot and an opacity map applied to it… I have tried connecting the out color or the out alpha of the map, with basically the same result.

I guess I could extract the hair from the RGB layer with material ID, but it’s going to be messy and it may require a lot of work to match it to the rest of the character if I change the lighting dramatically…

Any ideas?

Thank you!