Exponential file size increase (SectionTools bug?)

Hello everyone,

I’m experiencing an odd issue where my Rhino .3dm files grow exponentially in size each time I save, reopen and resave them. At first, I suspected invalid geometry, but that doesn’t seem to be the cause. The only common factor I’ve found so far is SectionTools, though I’m not entirely certain it’s the culprit.

Here’s my setup:
I have multiple files: Hull Plate, Frames, Longitudinals, Main Deck, etc.
Each of these files can be used as a reference block in other files, with the following preferences:

If, for example, the Hull Plate.3dm file contains a section created with SectionTools and I reference it (Insert cmd) inside Frames.3dm, the size of Frames.3dm increases each time I close, reopen, and save it.

Has anyone encountered a similar problem or discovered a workaround? Any tips or insights would be greatly appreciated!

Thanks in advance.

Hi Karlo -
I’m not seeing that here in a quick test. I inserted File to Insert as Reference.3dm in a new file and added a rectangle. Save that new file, exited Rhino, and reopened that new file. Create a circle, saved and exited Rhino. The file size did not increase.

Please run the Rhino SystemInfo command and copy-paste the output here.
-wim

@wim I was able to reproduce the issue using your file. I duplicated it multiple times, and in each copy, the other files were inserted as block references. Now, whenever I save a file (e.g., “…Reference4”), its size increases. This might not be as noticeable with smaller files, but for larger files—several megabytes in size—the increase is significant. For instance, a file that originally measured 28MB grew to 3GB after just a few saves.

Files.zip (323.3 KB)

Rhino 8 SR16 2025-2-11 (Rhino 8, 8.16.25042.13001, Git hash:master @ d0f731de6fe2c5fdcad78ad80faf154307815f18)
License type: Commercial, build 2025-02-11
License details: LAN Zoo Network Node

Windows 11 (10.0.26100 SR0.0) or greater (Physical RAM: 31GB)
.NET 7.0.20

Computer platform: LAPTOP  - Plugged in [100% battery remaining]

Hybrid graphics configuration.
  Primary display: Intel(R) Arc(TM) Pro Graphics (Intel) Memory: 2GB, Driver date: 9-13-2024 (M-D-Y).
    > Integrated graphics device with 4 adapter port(s)
        - Windows Main Display is laptop's integrated screen or built-in port
        - Secondary monitor attached to adapter port #1
        - Secondary monitor attached to adapter port #2
  Primary OpenGL: NVIDIA RTX 500 Ada Generation Laptop GPU (NVidia) Memory: 4GB, Driver date: 9-2-2024 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 553.05
    > Integrated accelerated graphics device (shares primary device ports)
        - Video pass-through to primary display 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: 9-2-2024
  Driver Version: 31.0.15.5305
  Maximum Texture size: 32768 x 32768
  Z-Buffer depth: 24 bits
  Maximum Viewport size: 32768 x 32768
  Total Video Memory: 4094 MB

Rhino plugins that do not ship with Rhino

Rhino plugins that ship with Rhino
  C:\Program Files\Rhino 8\Plug-ins\Commands.rhp	"Commands"	8.16.25042.13001
  C:\Program Files\Rhino 8\Plug-ins\rdk.rhp	"Renderer Development Kit"	
  C:\Program Files\Rhino 8\Plug-ins\RhinoRenderCycles.rhp	"Rhino Render"	8.16.25042.13001
  C:\Program Files\Rhino 8\Plug-ins\RhinoRender.rhp	"Legacy Rhino Render"	
  C:\Program Files\Rhino 8\Plug-ins\rdk_etoui.rhp	"RDK_EtoUI"	8.16.25042.13001
  C:\Program Files\Rhino 8\Plug-ins\NamedSnapshots.rhp	"Snapshots"	
  C:\Program Files\Rhino 8\Plug-ins\MeshCommands.rhp	"MeshCommands"	8.16.25042.13001
  C:\Program Files\Rhino 8\Plug-ins\IronPython\RhinoDLR_Python.rhp	"IronPython"	8.16.25042.13001
  C:\Program Files\Rhino 8\Plug-ins\RhinoCycles.rhp	"RhinoCycles"	8.16.25042.13001
  C:\Program Files\Rhino 8\Plug-ins\Toolbars\Toolbars.rhp	"Toolbars"	8.16.25042.13001
  C:\Program Files\Rhino 8\Plug-ins\3dxrhino.rhp	"3Dconnexion 3D Mouse"	
  C:\Program Files\Rhino 8\Plug-ins\Displacement.rhp	"Displacement"	
  C:\Program Files\Rhino 8\Plug-ins\SectionTools.rhp	"SectionTools"	

1 Like

Thanks, Karlo -
I put this on the list as RH-86206 File IO: File Size Increases with Each Save in Unchanged Model
-wim

1 Like

Hi Karlo,

I think I need more details because, with your example.zip file, I’m not able to repeat what you’re seeing. I do see an initial increase on the first save of the session but I think I’ve been able to tie that increase to the creation of a preview image. I’m not seeing a file increase each time I save in the same session. On Mac I do not see the file increase after that, even after closing Rhino, reopening and saving again. On Windows, I do see a modest increase after closing Rhino reopening and saving again. I think I can attribute that increase to SectionTools userdata.

I’m not seeing the huge increases you’re reporting for each save you make. That makes me think I’m not doing it right, at least not the same way you’re doing it. Can you please elaborate on the process you’re using to see the very large increases? Maybe it would be good if I had one of your large files to test with too.

Tim