CPU vs GPU rendering results

So one of my artists handed off a scene that he put together and when I render I get different results between GPU and CPU rendering:

CPU (correct):

GPU:

HOWEVER, my artist says that he is getting the same result with CPU and GPU renders.

He has a older GeForce card (2070 Super) while I have a 3070.

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Do you have all the textures on your end? If he’s getting identical results, it’s probably a file location issue; maybe a permission one.

Yeah, the scene was archived up into a zip and everything is loaded (I checked the File Path Editor). I also full privileges on my machine.

Are you rendering with an identical V-Ray and host platform version? Maybe you could attach the scene so we can take a look.

Here you go!

Allow access so I can download it.

My bad. Try it now:

Any luck opening it?

The differences are strictly linked to the VRayBlendMtl:
1. The VRayBumpMtl without a base shader (Airfeild_Normals_Spacing) is handled differently on CPU and GPU. Both do not work without a base shader. The major differences stem from here.
2. Opacity is not supported on GPU with VRayLightMtls (Dirt_Map_RGB_Overlay_mat)
3. MS_Soil_Mud has a normal map linked to the bump slot, but the mode is set to Bump.

Note that GPU and CPU handle normals differently, so differences are inevitable. Otherwise, we suggest choosing a render engine based on the needs of your project and sticking to it, rather than switching engines mid-production.

Thanks Aleksandar for taking a look at that.