Textures not rendering on GPU

[morganmcd]

I'm having an issue where the textures on my materials don't render when you using the GPU but render as expected with CPU. Happens with both progressive and bucket. Anyone else having this issue?

Thanks!
Morgan

[chakarov]

Hi, I need some more information about this case. OS, Houdini version, V-Ray versions - official or nightly? Also what's the material, what's the texture and where it is connected?

[morganmcd]

Hi Chakarov,
I'm using vray official release 41203 for Houdini 17.5.293 on Windows 10 (GPU: 2x RTX 2070)
The Material is a simple Vray Material with Diffuse, Roughness, and Normal textures in TGA format.
The Material is setup in the Mat context and assigned to the FBX mesh in the OBJ context.
The behavior happens in different scene files with different meshes and textures.

I'm also using some of these objects as scatter meshes on a heightfield scatter and when I do they lose their textures with both the CPU and GPU renderers, though this could be a different issue.

Happy to try a nightly build if you think that might help.

Thanks!
Morgan

[chakarov]

Hello again morganmcd ,I've tried several houdini and V-Ray versions with tga image connected to diffuse. It works normally.
Roughness is not supported on GPU. If you want to use normal bump, the imagefile with the normal map should be connected to "additional_bump" input of the BRDFBump node.
If you still have problems try to update your GPU driver, if the problem still exist I'll need a simple scene to investigate deeper.

[morganmcd]

Ok, thanks Georgy.

[chakarov]

Hi again, I just found that "bump_tex_color" where broken in GPU mode, but it is fixed now, the fix will be available soon in stable nightlies. This "additional_bump" works as workaround for now I guess.

[morganmcd]

Oh cool, thanks!

[Ambrozie]

Hi everyone,

I'm struggling to reproduce the Vray NormalBump similar to what I have in 3dsMax. In Houdini, I added the bump <UDIM>.tga in the bump slot, and the normal.<UDIM> in the "additional_bump" but I get no change. What Bump type should I choose, or what am I missing? Thanks

I'm using Houdini 18.0.348 and Vray build from 13.02.2020

See below the examples.

[chakarov]

Hello Ambrozie, can't tell what is wrong with your setup, but this is an example of material with displacement and normal bump whit texture tiles.

[Ambrozie]

Hi Georgy chakarov ,

thanks for the example. For some reason, I still can't get the fine details from the ''normal'' to show up. The material is set up in the exact same way, however, there are two differences in my scene: I am not using any displacement because I am fracturing the mesh and I am using tga instead of png texture sets.

With a Quixel Megascans texture as png works as expected.

So the tga textures seem to be the reason? There's probably something related to the color space ... or?

Thanks again, Ambrozie

[chakarov]

Hello again, can you send me just one of your normal textures at georgy.chakarov@chaosgroup.com, so I can reproduce the problem on our side.

[Ambrozie]

I'll send them, thank you!

[chakarov]

Hello again Ambrozie , I just checked again and compared how VFH and V-Ray for 3dsmax behave when normal bump is used. Looks like my file, which I uploaded earlier, is also wrong. Normal map should be connected to "bump_tex_color" and the Height map to "additional_bump". This should produce very similar result to what V-Ray in 3dsmax renders.
Here is the correct way to use normal bump.

[Ambrozie]

Thanks for getting back to me. Due to time constraints, I had rendered already the background terrain 3dsMax (Vray Next) and kept separately the Houdini stuff. Which brings me to a new issue . If I render with motion blur in Houdini, I get some geometry randomly not showing up in some of the frames.
Here's an example with and without motion blur. If I don't render with motion blur enabled all frames render correctly.



Do you have any suggestions? Thanks

[Ambrozie]

chakarov It seems I can't post two links in the same window, so here's the second one here. Motion blur issue - geometry randomly missing (just thinking this could belong to a separate thread).