VRay Light Select Element Workflows?

[erickdt]

Hi All,

 

I recently watched a video on the Chaos Group website about the VRay light select element and how it can be used to tweak lighting in post. In their example they used PDP Player which I do not have. That said, I am curious to know if anyone has any experience using this element with Photoshop/AfterFX and how that workflow works (in terms of other necessary elements and layer blending modes, etc.).

 

Thanks in advance!

 

E

[Corey Beaulieu]

I have only played around with it so my experience is light, but It all depends on a few things. What your file type is and which program you are comping in. The light select pass worked best in my playing around when it was a comped 32 bit color space. In photoshop it was a fairly straight forward process. A Linear Add or just plain Add blending mode in 32 bit mode allowed the light to simply add its intensity without clamping the whites. After Effects, however, was slightly different. once the files were brought in and the color space was set to 32 bit, I also had to tick the box that said blend colors using 1.0 gamma in the project settings. After that It was the same as photoshop with the blending mode. With the pass "added" in either program, you should be able to control how much or little it applies through the opacity.

 

I don't know what file tyoe you are saving or what type it works best with, but I usually save to EXR on half float, override set to 1.0.

 

I hope this helps and that others have more to add.

[erickdt]

I tried a similar experiment in Photoshop using more or less the same settings. In my case, the light select pass was being added to the "beauty pass" and therefore raising the intensity of the lighting too much. I think where I was going wrong was comping the light select pass with the beauty pass. What would be the recommended layer/pass setup to effectively use the light select element?

 

E

[Dave Buckley]

I'm also interested in the correct compositing workflow for using this in Photoshop, I can't help but think that this video is a lot of smoke and mirrors http://www.youtube.com/watch?v=VQISe90BzHg, what he's doing surely isn't possible with just the elements he renders out?

[erickdt]

I actually think I figured something out for this yesterday. Yesterday was the first time I was ever able to successfully render out a 32bit multi-layer EXR. In one of my experiments I used the light select element to define 4 seperate lighting groups. This was in addition to the typical VRay Specular, VRay Reflection, VRay Refraction, VRay Lighting, VRayGlobal Illumination, VRay Shadows and VRay Background.

 

Once the file rendered out I had a layer for each one of those groups as well as a VRay lighting pass. All were set to the Linear Dodge (Add) blending style. I turned my VRay lighting pass way down to like 10% which made it act more like a fill light and then was able to play around with the light groups individually by adjusting their levels, their hue/saturation, duplicating them etc. A pretty nifty functionality that I hope to add in to my workflow sometime in the not too distant future.

 

E

[ACHOMIRE]

Hello!

What I figured out is that this render pass could be used as completely desaturated layers put on Screen mode or Linear Dodge mode with (10-40 % oppacity) with solid color over it put on colour mode. You can thus change the light variations for instance in an interior scene.

The other way of implemting this render pass is by using it as a mask over a solid colour adjustment layer. Experiment!