Strange noise rendering behavior with GPU

[ghiom3d]

Hello I find an issue when using GPU an Vray Noise or Bercon Noise.

1-apply a noise on diffuse of a cube.
2- rendering with GPU IPR , you only have a blended color, not the 2 colors of the noise.
3- do a final render instead of IPR, you see the noise correct the firsts iterations of rendering and it's back to an united blended color.

with CPU no issues.

[Muhammed_Hamed]

I have came across this and probably forgot to report it
This used to work a while back I think, Both Vray noise and Bercon noise are supposed to be procedurally supported on GPU

[chakarov]

Hello guys, the issue is caused by one unsupported mode of the default mapping from V-Ray GPU, in order to use bercon noise you should assign V-Ray UV Channel Named to uvwgen input of the bercon node. It's a known limitation but unfortunately still not fixed.

[Muhammed_Hamed]

Thanks Georgy!
Seems like this limitation is in other V-ray plugins as well, but they usually have a UV channel already with bercons.. probably why I didn't realize

Thanks again for your help!

[chakarov]

That is right, the limitation is not Houdini specific, it's in the V-Ray GPU renderer and it's not related to bercon noise, but only the default mapping for procedural textures. I'll add an issue about that, to change this default uvwgen

[Muhammed_Hamed]

Awesome!

thanks Georgy!

[ghiom3d]

thanks Georgy !