Bug in "Object parent" material for nested blocks

This seems like a bug to me, because it doesn’t behave as promised in

I’m working with a large model split over many files.I demonstrate the problem with three files.

One file is a reusable part that must be painted to match its location in the model. Therefore its material is “Use Object Parent”.
(Pan head screw, 10mm, no tail.3dm)

One file uses two instances of the part. One instance is assigned a material, and the other one uses the layer material. In both cases the part renders as expected.
(Intercom socket box.3dm)

The final file contains a block instance of the second file. I expect the part to render as before. But, in a “Rendered” view it renders with the material of the overall block instance - which is its grandfather block instance. However, in a “Raytraced” view it behaves as I would expect.

Is this a bug or do I misunderstand something?
Thank you.

Pan head screw, 10mm, no tail.3dm (81.1 KB)
Intercom socket box.3dm (1.0 MB)
Kasten 22b.3dm (1.0 MB)

Hi David, I’ll take a look, thanks.

David, should the screws in the socket box file be on the Lid layer or Nuts and Bolts?



The physical objects in the screws file are on the “Nuts and Bolts” layer because the screw is supposed to be used in many different places on the overall model, and the model is spread over many layers and files. So, every file that inserts a screw (as a block) will acquire a “Nuts and Bolts” layer.

The screw block that I inserted in the socket box is placed on the “Lid” layer so that I can make the lid disappear completely, or move it around, or assign it a material, etc.


Hi David - thanks, yes, the instance layer is what I was asking about - I do see a problem here, I just have not sorted out where it occurs.

Can you please describe what you expect here?
I think V8 gets this right but I just want to make sure.

V8/WIP rendered display of the Kasten file:



Sorry, I should have shown you what happens on my version 7 SR31.


This is the Intercom Box file.
The material of the screws is assigned directly to the screw
block in one case, and is the “Lid” layer material in the other case.
Both of the screws appear as I expect in both of these modes.


And this is the Kasten file, which includes the intercom file as a block.

In Rendered mode, the screws take on the material of the overall object
which (in my understanding) is their grandparent. But I expected them to
have the material of their parent, just like before.

Or, to put it simply : the two viewing modes of the screws, rendered and
raytraced, should look much the same.

Am I making sense here?


Hi Dfavid - thanks - as far as I can see V8 gets this right. I’ll add a bug for the V7 rendered display mode, but be aware that we are winding down V7 and I can’t promise this will get fixed.



HI both of you.
I have the same problem. All our product files is made in AutoCAD build up with nested blocks.
I found a way to set everything on layer 0 to ByParrent but the rendered view in Rhino 7 was not showing right. Both shaded and raytraced view worked.
I just tested Rhino 8. And here all views are working.
Are there any chance it will be fixed in Rhino 7? We are not ready yet to switch to Rhino 8.

Hi Rasmus -

No. At this point, only severe crash bugs are considered for fixes in Rhino 7.