Gumball not aligned to object

Hi @Gijs

In GumballAutoReset doesn't work you looked at a problem with me about the Gumbal AutoReset. I thought the Gumbal AutoReset was the problem but im not so sure anymore, because I’m still experiencing the problem.

My problem is that blocks in my file get there gumbal placement misplaced. This happens randomly. Could be at a block is fine one moment, work some more come back to that block and its misplaced.

In the image you see a fairly simpel block where Rhino suggests that the gumbal is above it. But in fact there is nothing there, call it a ghost. This block was exported to new Rhino and still its misplaced.

Ive scaled that block like a million times bigger because the gumball is over 200.000mm away.

If you run GumballReset it go’s back to its origin.

I’m really not sure what is causing this misplacement, not sure if its something is that I do or just Rhino8 bug.

Gumball placement wrong.3dm (386.4 KB)


Rhino 8 SR8 2024-5-14 (Rhino 8, 8.8.24135.14001, Git hash:master @ 8c191427bc5c6c4e62f523a752d809f68897c3a5)
License type: Commercial, build 2024-05-14
License details: Cloud Zoo

Windows 10 (10.0.19045 SR0.0) or greater (Physical RAM: 32GB)
.NET 7.0.0

Computer platform: DESKTOP

Standard graphics configuration.
Primary display and OpenGL: NVIDIA GeForce RTX 2060 SUPER (NVidia) Memory: 8GB, Driver date: 3-8-2023 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 531.30
> Accelerated graphics device with 4 adapter port(s)
- Secondary monitor attached to adapter port 0
- 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: 8x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: High

Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 3-8-2023
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

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 8\Plug-ins\Commands.rhp “Commands” 8.8.24135.14001
C:\Program Files\Rhino 8\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 8\Plug-ins\AnimationTools.rhp “AnimationTools”
C:\Program Files\Rhino 8\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 8.8.24135.14001
C:\Program Files\Rhino 8\Plug-ins\RhinoRender.rhp “Legacy Rhino Render”
C:\Program Files\Rhino 8\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 8.8.24135.14001
C:\Program Files\Rhino 8\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 8\Plug-ins\MeshCommands.rhp “MeshCommands” 8.8.24135.14001
C:\Program Files\Rhino 8\Plug-ins\IronPython\RhinoDLR_Python.rhp “IronPython” 8.8.24135.14001
C:\Program Files\Rhino 8\Plug-ins\RhinoCycles.rhp “RhinoCycles” 8.8.24135.14001
C:\Program Files\Rhino 8\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 8.8.24135.14001
C:\Program Files\Rhino 8\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 8\Plug-ins\BlockEdit.rhp “BlockEdit” 8.8.24135.14001
C:\Program Files\Rhino 8\Plug-ins\Displacement.rhp “Displacement”
C:\Program Files\Rhino 8\Plug-ins\SectionTools.rhp “SectionTools”

This is a hard problem, since there will be not much info in that file to determine what caused the displacement. @Joshua_Kennedy do you have an idea what might be happening here?

Like you said, GumballReset is putting that back to where it’s expected. When you relocate in any gumball mode the orientation is saved. Here’s the relevant issue for saving it in the 3dm file. Undo support for gumball relocate necessitated saving the orientation for all modes on the object. There’s a saved CPlane frame for that object in the 3dm file. So at some point maybe you relocated the gumball?

Hi @Joshua_Kennedy,

I do not move the gumball itself but I do use _GumballAlignment quite a lot.

Its also 200 meters, away, nothing in my file is even remotely in that position.

Also, its not just this file, or this machine. I have seen it on my home and work pc, and in every file I work on. big blocks, small blocks, linked blocks, embedded blocks.
I’ve had case that I reset-ed the gumball, exited the parent block, opened/blockedited the parent block again and it was moved again.

It wasn’t in Rhino 7, and I have been using the _GumballAlignment since RH6 already. I’m not sure anymore if it was in the first release of RH8 of that it came with a later release.

To me it really seems like a Rhino8 problem but I just don’t know what specifically is causing it.

@Martijn did you scale the block, or the objects in the block?
Did you do that so that it would be easier to see the block item? Do you also have the file before that scale was changed?


Yes, the block has an 8x8x60mm boundingbox. The gumball was so war away that you might lose the block also otherwise I couldn’t make a clear screen shot.

I’m not sure if this is the same block (position wise), but I exported it again. This time unscaled.

Also this when _GumballAlignment is set to object

Gumball placement wrong unscaled.3dm (384.5 KB)

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Here is also a situation with a curve where the gumball is misplace.
Again I didn’t move the gumball, came back to the block and is was wack.

Curve with gumball misplacement.3dm (378.1 KB)

Do you model these blocks in different units than the file you’re importing them to?

i am experiencing same thing

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Nope, always the same template and units (mm)

Thanks for staying with me and reporting this stuff. All these files show the same thing which is a saved gumball orientation in the user data already that’s being used. How it’s getting to the wrong spot in the first place is the question. If you can give me the step-by-step of what exactly you do leading up the orientation going wrong it would help immensely. I understand this can be tricky since it seems random. So far while investigating this I’ve dug up RH-82058 where scaling isn’t being applied to the saved orientation for block instances on import when unit systems vary.

Hi @Joshua_Kennedy,

I’ll try to keep an eye out for this problem this week, maybe I can see some kind of correlation.
We are running some pythonscripts, but our IT department has told me that the chance that its related to a script thing is almost 0% (especially since we didn’t have this problem in Rhino7).

@ivan.galik, maybe you can also help with tring to find out what is causing this?

Hi @Joshua_Kennedy
Why does Gumball not return to its primary position like RH7.
I did not press GumballReset in Rh7, Gumball automatically returns, but in Rh8 it saves the rotation shape even after exiting and returning.

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I think this is the crux of the problem.

This behaviour is different in RH8 vs RH7 and this give a lot of problems. I still don’t know why my gumballs are so much displaced but if there were to be reset every time you click the object it solves everything.

I’m not sure how this will work with the new function where you deliberately move to gumball to a new position (using the double click), but I’m sure McNeel can think of a solution for this.

@Joshua_Kennedy, @Gijs, would love to hear your input on this.

If there is a change in settings in v8, an option must be added to allow the user to operate like in v7.

I wonder if you found that a good thing in Rhino 7? To me the behavior in the Rhino 8 clip is more useful, don’t you think?

Personally I liked the RH7 settings,
If I would like gumball that rotated then I switch the gumball orientation to object.

Making this an setting works for me as well. then you can choose the behaviour yourself, constant reset or remember transformation