Hey Guys,
This has been bugging me for a very long time:
When I use gumball extrude of a surf I sometimes get polysurfs while when I do it via ExtrudeSrf it comes out as it should
I dont think it has always been like that, it sneaked in during a rhino version upgrade or a SR release. I would love to be able to have same behavior as ExtrudeSrf.
Can this be done please?
Similar topic here:
Why do extruded fillet curves result in polysurfaces instead of surfaces? - Rhino - McNeel Forum
Similar indeed but not extrusion object related, My example digs closer to the cause of the issue.
I would really like to see a solution here.
It’s one of those things that are seen but not spoken of 
I thought this setting might help but it does not.
Rhino 9 SR0 2025-6-3 (Rhino WIP, 9.0.25154.12305, Git hash:master @ b2cb56992953ffb81127629b4e1bf5c51cae7c53)
License type: Commercial, build 2025-06-03
License details: Cloud Zoo
Expires on: 2025-07-18
Windows 11 (10.0.26100 SR0.0) or greater (Physical RAM: 128GB)
.NET 9.0.5
Computer platform: DESKTOP
Standard graphics configuration on OpenGL
Primary display: NVIDIA RTX A5000 (NVidia) Memory: 24GB, Driver date: 5-12-2025 (M-D-Y). OpenGL(4.6.0 NVIDIA 573.24)
> Accelerated graphics device with 4 adapter port(s)
- Windows Main Display attached to adapter port 0
- Secondary monitor attached to adapter port 1
Secondary graphics devices.
NVIDIA Quadro K2200 (NVidia) Memory: 4GB, Driver date: 5-12-2025 (M-D-Y).
> Accelerated graphics device with 4 adapter port(s)
- There are no monitors attached to this device!
OpenGL Settings
Safe mode: Off
Use accelerated hardware modes: On
GPU Tessellation is: 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: 5-12-2025
Driver Version: 32.0.15.7324
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 24564 MB
Rhino plugins that do not ship with Rhino
C:\Program Files\Rhino 9 WIP\Plug-ins\ConstraintsUI.rhp “Constraints UI” 9.0.25154.12305
Rhino plugins that ship with Rhino
C:\Program Files\Rhino 9 WIP\Plug-ins\Commands.rhp “Commands” 9.0.25154.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\WebBrowser.rhp “WebBrowser”
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoScript.rhp “RhinoScript”
C:\Program Files\Rhino 9 WIP\Plug-ins\IdleProcessor.rhp “IdleProcessor”
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 9.0.25154.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 9.0.25154.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 9 WIP\Plug-ins\MeshCommands.rhp “MeshCommands” 9.0.25154.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\IronPython\RhinoDLR_Python.rhp “IronPython” 9.0.25154.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoCycles.rhp “RhinoCycles” 9.0.25154.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 9.0.25154.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 9 WIP\Plug-ins\Displacement.rhp “Displacement”
C:\Program Files\Rhino 9 WIP\Plug-ins\SectionTools.rhp “SectionTools”
Extrude 9.3dm (5.7 MB)
How is your CreaseSplitting option setup ?
And the Gumball “Merge faces after extrude” option
Did not know about CreaseSplitting, thanks @skysurfer ! Unfortunately no effect though.
Merge faces after extrude has no effect either
@Joshua_Kennedy may have some ideas for this-
Only works on coplanar surfaces…
