my Problem was to generate a very dark shadow in a room, with active GI=on. With the material "VrayOverrideM" you can adjust shadow lightness, thats it. But I was not able to get it darker with this function. Only more transparent. So I found a solution to render shadows in VRAY more dark, or 100% dark / black. (also the opposite way, 100% white. This could be usefull in special cases) In normal situations darker shadows are not always necessary. We know, it could be handled in post. But if you make test renders, final renders, tweak your scene it is very handy, cause you don´t have to switch into a post-application and struggle with lots of object-channels only for one picture. Solution: 1. add a VrayLight-tag to your light-source 2. inside this tag, click on "texture" and add a layer 3. inside this layer create 2 folders 4. inside these folders, place a "effect" named "bcs" (brightness/contrast/saturation) 5. every bcs gets -100% brightness 6. the top folder / first folder should have "exclusion" as layer definition Thats it. Now you can adjust the darkness-level of the shadow. Also you can place a colorize-effekt into the folder, when you want. Perhaps this solution could be usefull for your projects. With this workflow you are able to tweak shadows like with the C4D native renderer. If someone know a more elegant way to adjust, to darken shadows with VRAY, it would be nice to post it here. cheers des.