Bug: Material not listed in panel

Can you please check this file?
bug Material panel.zip (15.3 MB)

There’s a box with a material on it, but the mat does not show up in the Material panel, only in the Properties of the box.
Filter in the Mat panel is set to “Show all materials”.

I see this too with this file. I’ve logged it as RH-64778 Material does not show up in Materials panel.

1 Like

Hi @Eugen,

The material has been set as ‘hidden’ and then saved like that. However, I don’t know how the material got set as hidden. I’m not aware of any UI that allows this. I think it can only happen if a plug-in is deliberately coded to hide it. Of course, if the material is hidden, it shouldn’t even appear in Properties, so I’ll have to find a way to fix that.


here on Rhino 7 SR7 2021-5-11 no problem.

Thanks everyone!
Interesting. Never heard of hidden materials.
However, the material was part of nested blocks in the original scene.

@Eugen Hidden materials have been in Rhino for quite a while, but no one was using them. When someone started trying to use them, we found that they had stopped working due to an oversight during an unrelated code change. I fixed that, but I forgot Properties.

This is a little confusing. Just to be clear, the actual bug is that the material appears in Properties, and shouldn’t. It also should not appear in the tree as shown by @eddi. This bug was fixed in SR8 on May 18th which is why eddi can still see the material in the tree in SR7.


Thanks, John!
Is there a way to unhide all the materials? Or what is the best way now to fix the scene where hidden mats occur, however that happened?


Here’s the thing: hidden materials were added to allow plug-in developers to hide materials that they never want people to see. So you’re not ‘allowed’ to unhide them. Are you using any special plug-ins that could have set the material to hidden? If you are, I could ask the plug-in developer what their intentions are.


My only idea would be VisualArq, but my colleague who created the scene does not have it. Will investigate.
Thank you!

Hi again,
could not get rid of that ‘hidden material’ problem in my scene. It’s making things pretty complicated.
Would it be possible to ‘unhide’ all materials with a few lines of python?

Hi Eugen -

Have you updated to the Rhino 7.8 Service Release Candidate?
The final 7.8 version is “just around the corner” waiting for some new UI text to be translated in all supported languages.

Thank you, Wim!
That did not help. The problem appears even in fresh scenes after some time: objects have a certain material, but it is hidden in the Material panel. My workaround is to use the ‘Match’ button.

Hi Eugen -

Apparently, this is how this is now supposed to work:

  • In plain vanilla Rhino, you can’t create materials that don’t show up in the Materials panel
  • Plug-ins are allowed to create materials that don’t appear in this panel
  • A “hidden” material will always show up in the object’s properties

Please correct me if I’m wrong - I am guessing that you find it problematic that objects are assigned a material that is hidden. Based on the above, you will need to find out which plug-in is doing this and contact the developers of that plug-in to see if this can be changed.

I have the same problem. I’m not using any rendering plugin.

Materials were created in vanilla Rhino. Object properties are not showing which hidden material is assigned to the geometry.

I find out about this problem when I couldn’t make a new material because “Name already in use”.

System Info

Rhino 7 SR9 2021-7-15 (Rhino 7, 7.9.21196.07001, Git hash:master @ a1dd75a58c25c687e78697cfd8dd921026123719)
License type: Educational, build 2021-07-15
License details: Cloud Zoo

Windows 10.0.19042 SR0.0 or greater (Physical RAM: 32Gb)

Computer platform: LAPTOP - Plugged in [93% battery remaining]

Non-hybrid graphics configuration.
Primary display and OpenGL: NVIDIA GeForce GTX 1070 (NVidia) Memory: 8GB, Driver date: 6-21-2021 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 471.11
> Integrated accelerated graphics device with 4 adapter port(s)
- Secondary monitor is laptop’s integrated screen or built-in port
- Windows Main Display attached to adapter port #1

OpenGL Settings
Safe mode: Off
Use accelerated hardware modes: On
Redraw scene when viewports are exposed: On
Graphics level being used: OpenGL 4.6 (primary GPU’s maximum)

Anti-alias mode: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: High

Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 6-21-2021
Driver Version:
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 8 GB

Rhino plugins that do not ship with Rhino
C:\Program Files\Rhino WIP\Plug-ins\Karamba\License\Karamba3D_LicensePlugin_Rhino7.rhp “Karamba3DLicense”
C:\Program Files\Rhino WIP\Plug-ins\Tibidabo\Tibidabo.rhp “Tibidabo”
C:\Program Files\Rhino WIP\Plug-ins\Tibidabo\VisualARQ.rhp “VisualARQ”
C:\ProgramData\McNeel\Rhinoceros\7.0\Plug-ins\Datasmith Rhino Exporter (d1fdc795-b334-4933-b680-088119cdc6bb)\DatasmithRhino7.rhp “Datasmith Exporter”
C:\ProgramData\McNeel\Rhinoceros\7.0\Plug-ins\Twinmotion Direct Link 2020.2 (e24ee14a-9514-47da-8fe6-f6e61b20160e)\Twinmotion Direct Link 2020.rhp “Twinmotion Direct Link 2020”
C:\Users\USER\AppData\Roaming\McNeel\Rhinoceros\packages\7.0\IntelDenoiser\0.6.0\IntelDenoiser.Windows.rhp “IntelDenoiser.Windows”
C:\Users\USER\AppData\Roaming\McNeel\Rhinoceros\packages\7.0\NVIDIADenoiser\0.4.0\NVIDIADenoiser.Windows.rhp “NVIDIADenoiser.Windows”
C:\Users\USER\AppData\Roaming\McNeel\Rhinoceros\packages\7.0\SubstanceImporter\2.0.0\Substance.Win.rhp “SubstanceImporter”

Rhino plugins that ship with Rhino
C:\Program Files\Rhino WIP\Plug-ins\Commands.rhp “Commands” 7.9.21196.7001
C:\Program Files\Rhino WIP\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino WIP\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 7.9.21196.7001
C:\Program Files\Rhino WIP\Plug-ins\RhinoRender.rhp “Legacy Rhino Render”
C:\Program Files\Rhino WIP\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 7.9.21196.7001
C:\Program Files\Rhino WIP\Plug-ins\rdk_ui.rhp “Renderer Development Kit UI”
C:\Program Files\Rhino WIP\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino WIP\Plug-ins\IronPython\RhinoDLR_Python.rhp “IronPython” 7.9.21196.7001
C:\Program Files\Rhino WIP\Plug-ins\RhinoCycles.rhp “RhinoCycles” 7.9.21196.7001
C:\Program Files\Rhino WIP\Plug-ins\Grasshopper\GrasshopperPlugin.rhp “Grasshopper” 7.9.21196.7001
C:\Program Files\Rhino WIP\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 7.9.21196.7001
C:\Program Files\Rhino WIP\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino WIP\Plug-ins\Displacement.rhp “Displacement”

material problem.3dm (1.3 MB)


I tidied up my file, created new PBR materials and now they disappear from the list. It’s a pretty bad problem.

You still have VisualARQ, which is I believe one of the plug-ins that has code to create hidden materials.

Does this still happen with VisualARQ and Tibidabo disabled? Probably also a good idea to disable Datasmith and Twinmotion. Not sure about Karamba. About the denoisers and the substance importer plug-ins I know they don’t created hidden materials.

Hi @Czaja,

There are a number of things happening here:

  • I can confirm that there are several hidden materials in the model. How these got hidden is a mystery unless they were created as hidden by VisualARQ or some other plug-in. Rhino does not deliberately hide materials itself.
  • The fact that you can’t see the material at all in Properties is a bug. You should be able to see it there instead of ‘Click to assign’. I will fix this bug as soon as possible.
  • Once a material is set as hidden, it is hidden forever even if you disable the plug-in that hid it. So disabling VisualARQ as Nathan suggested will not unhide the materials.

I will speak to the VisualARQ developer and find out how he’s using this hidden feature and what the purpose is.

Thanks for your patience while we get this figured out…


1 Like

@johnc I did not ask if hidden materials became unhidden after disabling the suggested plug-ins, but rather whether with those disabled the following still happens:

Hi @Eugen and @Czaja,

This is a bug in the last version of Tibidabo, a shared plug-in of VisualARQ and Lands. We asked McNeel to support hidden materials so Lands can hide some materials that are not meant to be used by users, but a bug was setting other materials as hidden. Our testers didn’t catch this issue because we tested VisualARQ and Lands with the latest version of Rhino available when we published VisualARQ, which was Rhino 7.7, and hidden materials is a new feature in Rhino 7.8.

I’ve already fixed the bug, and we’ll publish the new version today after we test it correctly, under Rhino 7.8. Don’t worry; your materials are there, and there is nothing lost. When you open the file again with the last version of VisualARQ or Lands, materials that were set hidden incorrectly will be shown again.

Sorry for any inconvenience caused!




Thanks for checking things up. I did as much testing as I could at the time. Fortunately, it wasn’t any important project.

Here’s the bug for the Object Material Properties problem: