Problems editing a SubD object that has been extracted

I’m having issues working with/editing SubD objects that have been extracted from another mesh.

Process goes like this -

  1. Select some faces of a working SubD object to extract.
  2. Extract surface on selected faces.
  3. Try to Extrude SubD, Apend faces to SubD or Insert point to mesh. These commands just don’t seem to work on the newly extracted faces.

Am I missing something fundamental? Or maybe a bug?

Hi Rob - as far as I can see this works - can you post an example?


Hmmm, maybe I should see if I’m on an old service release and need to update…

In the meantime, file attached…

cartest-problem.3dm (186.2 KB)

The problem SubD is on it’s own layer and has been moved outboard slightly for clarity. It’s been extracted from the larger inboard side glass SubD (which incidentally is mirrored).

Thanks for taking a look Pascal!

Hi Rob - that one (red) works here - but I notice the underlying SubD is disjoint, which is a little odd too.

Please run SystemInfo in Rhino and post the results.


[quote=“pascal, post:4, topic:137926”]

That underlying SubD started off as one larger surface which I then divided up and deleted some faces to create the door gap between the two bits of glass.

System info below…

[/quote]Rhino 7 SR13 2021-12-14 (Rhino 7, 7.13.21348.13001, Git hash:master @ 7696723f74a63695b3c372a89110c0ca8c78b890)
License type: Commercial, build 2021-12-14
License details: Stand-Alone

Windows 10.0.19043 SR0.0 or greater (Physical RAM: 64Gb)

Computer platform: DESKTOP

Standard graphics configuration.
Primary display and OpenGL: NVIDIA GeForce RTX 3090 (NVidia) Memory: 24GB, Driver date: 1-28-2022 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 511.65
> Accelerated graphics device with 4 adapter port(s)
- Windows Main Display attached to adapter port #0

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: 8x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: High

Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 1-28-2022
Driver Version:
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 24 GB

Rhino plugins that do not ship with Rhino
C:\Program Files\Rhino 7\Plug-ins\Maverick\maverick_7.rhp “Rhino to Maverick”
C:\Program Files\SimLab\Plugins\SimLab Rhino Integration\SimLabComposerIntegration.rhp “SimLab Composer Integration”

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 7\Plug-ins\Commands.rhp “Commands” 7.13.21348.13001
C:\Program Files\Rhino 7\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 7\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 7.13.21348.13001
C:\Program Files\Rhino 7\Plug-ins\RhinoRender.rhp “Legacy Rhino Render”
C:\Program Files\Rhino 7\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 7.13.21348.13001
C:\Program Files\Rhino 7\Plug-ins\rdk_ui.rhp “Renderer Development Kit UI”
C:\Program Files\Rhino 7\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 7\Plug-ins\RhinoCycles.rhp “RhinoCycles” 7.13.21348.13001
C:\Program Files\Rhino 7\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 7.13.21348.13001
C:\Program Files\Rhino 7\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 7\Plug-ins\Displacement.rhp “Displacement”

Just updated to the latest SR (7.15.22039.13001) and I still can’t do anything with that red surface. How odd!

Hi Rob - I cannot imagine why there would be a connection, but just to make sure, please block/disable

Maverick\maverick_7.rhp “Rhino to Maverick"
SimLabComposerIntegration.rhp “SimLab Composer Integration”

in Options > Plug-ins page, then close and re-open Rhino. Any different?


I disabled those, restarted, but still couldn’t Extrude SubD the edges of that red surface…

Hi Rob - what happens in ExtrudeCrv? Are you allowed to select the edges then it fails, or?


With the command ExtrudeSubD clicked it asks for “…faces and edges to extrude…” but I just can’t select anything on that red object.

Then if I type E for edgeloop it’ll let me select the edges (highlights them in yellow) then just doesn’t do anything after that, doesn’t even report a failure.

OK, got it now, thanks - ExtrudeSubD, I see that fails here too, I’ll add it to the pile. I was testing ExtrudeCrv with SubD output. AppendFace seems ok though, here.


Confirmed, AppendFace does work.

But ExtrudeSubD or InsertPoint don’t.

Hi Rob - thanks, I can reproduce this, extracting faces from your original. If you explode the disjoint SubD first, then ExtractSrf from one of the pieces, it all seems to behave.
RH-67441 Extracted subD faces do not behave

Oh! That’s interesting. Thanks Pascal, will make sure to do that in the future!