Vray Dirt - Occlusion and Consider same object issue

[thablanch]

I'm trying to achieve a shader base on borders with Vray Dirt.

What I want is the side of the piece to be darker than the center of the piece, in the diffuse. Therefore, a Vray Dirt, inverse, seems the logic way.

reference : http://docs.chaosgroup.com/display/VRAY3/VRayDirt

I do not want the floor and other pieces to affect the shader.

I'm using 'consider same object only'. When doing so, the other pieces are also affecting my result. Tried the include/exclude/result affect, but it is not better..

Is there something I do not get in this??

Thanks!

[Margarita.Stoeva]

Hello!

I believe this happens because of intersecting geometry. I'll forward the question to our developers.
In the meantime you can try to edit the intersecting objects until no polygons from them are inside the geometry that you want to shade with VRayDirt when its invert normal option is enabled.

Thank you for your feedback!

[thablanch]

I think it is the intersecting geometry as well, but I was reading the <consider same object only> a fix for this.

The mesh is imported CAD data, not really clean. So I could do it (modify the mesh), but would be quite long..

Thanks!

[Margarita.Stoeva]

The <consider same object only> would usually do its trick but with the invert normal enabled there is an issue. It's added to our bug tracking system.
Thank you for reporting! We'll keep you updated.

Best regards!

[thablanch]

Thanks!!!!

[thablanch]

finally went with 'isolation mode + baking AO map'. A quick way around

[Margarita.Stoeva]

I'm glad you found a solution that works for you until we fix this issue!
Thank you for sharing it.

Best regards!

[Margarita.Stoeva]

Hello!

We have improved the calculation of VRayDirt with "consider same object only" and "invert normal" enabled. The fix will be included in the next service pack.

Best regards!

[alexyork]

Great work. Dealing with messy imported CAD models is always a nightmare so anything like this to help with it is most welcome.