cpu vs gpu - diferent bump results

[lorenzo_spinola]

good morning everyone,
even if I have hardware that allows gpu render, I never used it on vray because of feature limitations at the moment.
But I'm trying it on scenes where I avoided using unsupported features.
If I read correctly on the docs, bumps should be the same, and bump material should work, but the bump looks totally different in the scene I attached, and bump material(when tested, I can't share the project but I can make a test scene) is not showing up.
Anything I should to make it the same?

[Muhammed_Hamed]

Hi lorenzo_spinola

You can use VrayColor2Bump texture after your bump map, this will help you get closer results between V-Ray and V-Ray GPU
If you are using VrayBumpMtl, you will need increased bump multiplier on GPU to make it visible. We are aware of this issue and will push a fix soon, ID for the issue is VGPU-5865

That being said, V-Ray and V-Ray GPU are separate render engines. They will produce different results, this is expected to happen and we don't aim at pixel parity
You should start your project with V-Ray GPU, better than swapping engines mid project

You could still compare performance between V-Ray and V-Ray GPU on your hardware, use 2500 Samples Limit for optimal performance and 2000-3000 LC Subdivs for interior scenes

If you have other questions, or if you are missing on a feature on GPU let me know.

Best,
Muhammed

[lorenzo_spinola]

Hi Muhammed,
using the hotfix 3 of vray now.

I'm in the case I'm using vray gpu for the first time for the whole project this time, and as you suggested above, time ago, I'm trying to crank up the bump value.
but even with 1000 as value nothing shows up.
are there still issues with bump for GPU?

Lorenzo