vrayClipper and vrayDirt result in undesired shading

[Armin Mueller]

HI,
I just found out that the vrayClipper with a mesh object produces
undesired shading on geo with shading networks that use vrayDirt.
One has to enable "work with transparency" on the vrayDirt node
and disable all shading on the clipper mesh object.
This is not immediately obvious and took me a while to find out.
Maybe the default behaviour of the clipper node could be modified
or the vrayDirt node could ignore a clipper object.
A small Demo scene is attached.

Best Regards
Armin

[yolov]

Although I downloaded and rendered your scene, I couldn't spot the problem. Could you upload a screenshot where it's easy to see? Maybe I'm just missing something.

[Armin Mueller]

Here is a screenshot that illustrates the problem. I have to uncheck primary visibility
and all other render parameters on the clipper mesh and have to enable "work with transparency"
on the dirtTexture to solve this. In a more complex scene this took a while to pinpoint.

I

[yolov]

Ah, now I get it Sorry about that. Now I know what you mean. Well, I think it is doing what it is supposed to, at least at first glance, but I might be wrong of course..

Looking at the scene now, it seems to be behaving like you would expect it too when the clipper_geo object is excluded from being affected by the dirt. I've simply added clipper_geo to the "result affect" set (and unticked "as inclusive set") and it is no longer occluded.
Have you tried this? Could it work for your case?

[Armin Mueller]

Now I am confused,
I thought the clipper mesh would be invisible for all objects in
the scene, be it reflection, refraction, shadows etc..
So I was surprised that it is visible to the vrayDirt Texture.

[yolov]

Hmm, it might not be the most intuitive thing, I agree. I'll forward this to the devs for consideration.

[Armin Mueller]

I thought so too. Thanks.