VRay Soft Shadows on CUDA

Hi to everyone,

asking here for help any VRay + Blender experienced users. VRay works well using standard computing methods (CPU or CPU RT) but I have problems using the CUDA rendering.

It seems that GI is always turned on when rendering on CUDA and Im able to turn off the light in the scene by simple unchecking the “Enabled” option but … under this is a checker for the “Shadow” option and it makes NO difference to my scene (the shadows are active despite this). The bigger problem for me is somehow the fact that also settings for soft shadows (Shadow radius UVW) are NOT working - means these are always sharp!

Try to set these values to 1.0 and with CPU rendering the shadows became soft but with CUDA not - why? Is there a way to solve this?

 Sincerely, Jan

PS: In fact this is not the only setting not working with CUDA, for example also the multiplier for the environment texture seems not to work with CUDA (again works fine with CPU) and more…

You will get soft shadows using a light that has a physical size. I’m guessing you are using the default Point Light. Change it to a Sphere Light.

I can’t answer about the global shadows switch; it may something that isn’t implemented for CUDA rendering. If you ask at the Blender section on the Chaos Group forum someone there will know:- http://forums.chaosgroup.com/index.php

Hi Organic,

this method only allow to change the softness of the shadows by resizing the sphere but one way or another its functional and helps so THX! On the other hand its interesting/wierd that when computing on CPU the point light works fine with soft-shadows ;).

Yep, also thinks that it depends with some implementation problems. But hey, that non-working environmental multiplier is strange - anyone knows?

 Sincerely, Jan

Environmental multiplier works fine with Gpu-Cuda, download the latest Vray for Blender and Vray Standalone.
And remember to set Hdri image node Vray settings > Color space: Linear


Hi Juha,

as U could see here:


I think that everything is setted-up fine and the multiplier (here 25) does NOTHING for me. Im using BlenderVRay 2.77 and VRay 3.10.01 I think.

 Sincerely, Jan

You have months/years old Standalone. Current V-Ray Standalone version 3.45.01 for x64.

3.45? But its NOT a stable its a nightly build … or not?

V3.45 is nightly build, stable 3.2 and 3.3 are here.
Ask [email protected] for stable v3.4 link if you cant “trust” nigthly builds.

Yep, looks like everything is working now with 3.4x - THX mate!!!

 Sincerely, Jan