Issue with material displacement

[rock9]

I'm trying to make a pebble material. The displacement shows up fine in the asset editor but the material turns to be flat in the final render.



I checked in the settings for switches and the displacement in turned on.


I'm using Sketchup 2020 and Vray version is 4.20.03

Please help.

[nikoleta.garkova]

Hi rock9

Keep in mind that for Displacement to work, it should be applied to the outside of a Group.

This is a standard and expected behavior linked to the way SketchUp functions and more specifically how it handles geometry. In short, geometry, which is not Grouped (Make Group) or made into a Component (Make Component) lacks certain functionalities.
I've prepared a simple visual example for you to check: http://ftp.chaosgroup.com/support/sc...7_12-51-45.mp4

[rock9]

Hi rock9

Keep in mind that for Displacement to work, it should be applied to the outside of a Group.

This is a standard and expected behavior linked to the way SketchUp functions and more specifically how it handles geometry. In short, geometry, which is not Grouped (Make Group) or made into a Component (Make Component) lacks certain functionalities.
I've prepared a simple visual example for you to check: http://ftp.chaosgroup.com/support/sc...7_12-51-45.mp4

Thanks a lot!. It worked. The video is super helpful!


However, my pebbles have got many bumps. Is it due to the quality of texture or something else?



The image file for texture is the same as the one in original post.

One more question. When I change the displacement amount slider, no changes occur. Whether it is 0.25, 1.8 or 6. Why is it so?

[nikoleta.garkova]

This is probably due to the fact you're rendering in Interactive mode - try to stop the render before/after you make a change, re-render again and it should appear with the change applied.

[konstantin_chaos]

However, my pebbles have got many bumps. Is it due to the quality of texture or something else?

The texture itself is the reason.
You'll have to use a proper height map for better results.
You can try one of the scanned textures.com maps lithe this one:
https://www.textures.com/download/3dscans0392/132961
Just download the Height and use it as a displacement in V-Ray,

[rock9]

The texture itself is the reason.
You'll have to use a proper height map for better results.
You can try one of the scanned textures.com maps lithe this one:
https://www.textures.com/download/3dscans0392/132961
Just download the Height and use it as a displacement in V-Ray,

Thanks. I'll do it and get back to you. Moreover, the link you've given has maps for normal, roughness and ambient occlusion. How do I use them in V-ray for better output of the texture?

[konstantin_chaos]

Normal - Can be used in the Bump texture slot of the V-Ray material. Just make sure to select the Normal Map mode. Additionally you should specify Color Space: Rendering Space(Linear) for the Bitmap after loading it.
Roughness - Can be used in the Reflection Roughness texture slot. To see it set the Surface Control: Use Roughness in the Reflection material parameters. Additionally you should specify Color Space: Rendering Space(Linear) for the Bitmap after loading it.
Ambient Occlusion - The occlusion map is commonly used in games. You usually don't have to use it in V-Ray. If you still want to, you should probably multiply it on top of the diffuse texture. It'll make cavities appear darker. Multiplying it on top of the reflection / specular map also makes sense.