How to place a shadow to a HDRI-Background in CUDA-Mode?

[Kissling]

Hello,
I need urgent help with the following problem:

Precondition:
I work exclusively with the CUDA engine in CUDA + CPU mode!

V-Ray Version 6

Task:
I want to insert an object in a background image (HDRI) and get the shadow in the background.

In V-Ray 5 I had no Problems with this task.

Unfortunately, this does not work for me as shown in the following video:
https://www.youtube.com/watch?v=mMmv2GtfImE
and
https://www.youtube.com/watch?v=IuBxbY4R_bo at time 4:50

I have tried all possible combinations in the wrapper-Material.
Unfortunately without success.

If I calculate only I im in the CPU engine I get the shadow displayed in the VFB.

Thank you very much for a very quick help.

Regards Ronald

[Peter.Chaushev]

Hello, Ronald,

Thank you for reaching out!
We have identified the issue preventing the matte effect of Wrapper materials to appear when using V-Ray GPU.
An upcoming hotfix will contain a permanent solution for it.

In the meantime, there are a couple of workarounds you can use to overcome the issue:

• Workaround A:
  - Open the SketchUp Ruby Console (Window > Ruby Console or Extensions > Developer > Ruby Console depending on the version of SketchUp installed).
  - Paste the following script in the console. Make sure you substitute Wrapper_v6 with the actual name of your Wrapper material and keep the "/" in front of the name. Then, press 'Enter'.
  

  scene = VRay::Context.active.scene
  	scene.change {
  	scene["/Wrapper_v6"][:alpha_contribution_tex] = -1
  	}

• Workaround B:
  Use a Matte Wrapper material created in V-Ray 5. This can be done by opening the V-Ray Asset Editor and load a V-Ray 5 Wrapper vrmat file (the 'Import Asset File' located at the footer of the Asset Editor).
  If you have the V-Ray 5 Material Library still existing on your system, simply navigate and load the following file.
  %UserProfile%\Documents\V-Ray Material Library\AEC\materials\v5.0\Materials\Diagrammatic\ Matte Shadow Receiver.vrmat
  Alternatively, download and load it from here: Matte Shadow Receiver.zip

Hope this helps!

Kind regards,
Peter

[konstantin_chaos]

Hi Ronald,

I just want to notify you that V-Ray 6 for Rhino, hotfix 1 was recently released and it addresses the Wrapper issue.
Note that materials created with the official V-Ray 6 or the beta will have to be re-created to work correctly.

Konstantin