CPU vs GPU rendering results

[hunter_williams]

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.

[hermit.crab]

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.

[hunter_williams]

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.

[hermit.crab]

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

[hunter_williams]

Here you go!

https://drive.google.com/file/d/1Dba...ew?usp=sharing

[hermit.crab]

Allow access so I can download it.

[hunter_williams]

My bad. Try it now:

https://drive.google.com/file/d/1Dba...ew?usp=sharing

[hunter_williams]

Any luck opening it?

[hermit.crab]

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.

[hunter_williams]

Thanks Aleksandar for taking a look at that.