Really bad behaviour simple surfaces


bad.3dm (282.6 KB)

try to make block out of this object or just delete planar face and run cap.
surfaces get destroyed. its close to world origin so this should not be any problem since these are super simple surfaces (single curvature). its maddening. i just moved outer faces in world x and it ruined it all.

To fully replicate the issue follow this:
-get basic profile out of this shape by boolean splitting it
-stretch (move faces) it long enough
-boolean difference the skew part
-once it is not only extrusion like object try to move faces in X and it will destroy the surfaces even if it should not, everything was modelled correctly with high precision and simple operations

Rhino 7 SR24 2022-11-4 (Rhino 7, 7.24.22308.15001, Git hash:master @ cb2ad12922ceb989b185972675bb705a00abb97d)
License type: Commercial, build 2022-11-04
License details: Cloud Zoo

Windows 10 (10.0.19045 SR0.0) or greater (Physical RAM: 32Gb)

Computer platform: DESKTOP

Standard graphics configuration.
Primary display and OpenGL: NVIDIA GeForce RTX 3060 (NVidia) Memory: 12GB, Driver date: 6-8-2023 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 536.23
> 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: 6-8-2023
Driver Version:
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 12 GB

Rhino plugins that do not ship with Rhino
C:\Users\Ivan\AppData\Roaming\McNeel\Rhinoceros\packages\7.0\AntFarm\0.0.20-beta\AntFarm.rhp “AntFarm”
C:\Users\Ivan\AppData\Roaming\McNeel\Rhinoceros\BlockEditNew\BlockEditNew.rhp “BlockEdit”
C:\Users\Ivan\AppData\Roaming\McNeel\Rhinoceros\packages\7.0\EleFront\4.2.2\ElefrontProperties.rhp “ElefrontProperties”
C:\Program Files\Chaos Group\V-Ray\V-Ray for Rhinoceros\V7\VRayForRhino.rhp “V-Ray for Rhino”

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 7\Plug-ins\Commands.rhp “Commands” 7.24.22308.15001
C:\Program Files\Rhino 7\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 7\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 7.24.22308.15001
C:\Program Files\Rhino 7\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 7.24.22308.15001
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” 7.24.22308.15001
C:\Program Files\Rhino 7\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 7.24.22308.15001
C:\Program Files\Rhino 7\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 7\Plug-ins\Displacement.rhp “Displacement”
C:\Program Files\Rhino 7\Plug-ins\Calc.rhp “Calc”

Hi @ivan.galik
Although it seems like something you COULD do, using move on sub-objects (surfaces) that are part of non-planar (eg. cylindrical) surfaces is a really bad idea. If you turn on your isocurves you can see how bad it looks (I’ve just moved the cylindrical end out a bit).

The solution is to extract the surfaces you want to move, move them and then extend the surfaces you need to extend (or trim, if you need to shorten the object).
In V8 it’s a whole new game. With the PushPull command, you can do exactly what you are trying to do with no repercussions (well, that’s the idea, and it works most of the time).
HTH, Jakob


This is a common problem in Rhino 7, this is why I always extract the surfaces I want to modify, then untrim them all, do the desired changes, trim again and finally join everything together. It’s the only working approach in Rhino 7 that preserves the state of the original surfaces.

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it is shocking that with two operations (boolean difference, move edges) you end up with complete mess. This is unacceptable for me. This must be fixed even if there is new feature (pushpull) which can handle it better. @wim what do you think of this?

this is too serious of a problem to be neglected. it looks like totally fundamental thing. i can understand failures with super complicated cases and far from origin where precision is lost. but not handling some basic geometry.

You’re not understanding, it’s not a ‘fundamental’ thing at all, you’re using a tool that was never meant to work on anything more complicated than boxes. A newer one is on the way.

And what’s the deal with ‘world origin?’ The display can get messed-up easily when things are far from origin–the display is not double-precision!–but for modeling to get screwy you have to go…waaaaaaaaay farther away.

direct editting with gumball is fundamental for me. and why should it work just with boxes? its rhino 7 and not rhino 1 or 2 :smiley:

Well obviously you are mistaken. This isn’t mesh modeling.

Hi Ivan -

Since you ask me…

I don’t think I could put it any better.

hmm i dont think that moving a face in other cad (based on parasolid for instance) would cause such mess even if its nurbs and not mesh. i know parasolid is different league but still. also the complicated procedure just to avoid this as @Rhino_Bulgaria described sounds like too much.

That’s basic NURBS modeling workflow, that’s what’s “fundamental.”

Now imagine trying to figure out how to do all that stuff automatically…

I had issues with Plasticity which changed the original topology of my NURBS models created in Rhino.

I often work with round pipes whose cut ends are very similar to your example, so I pretty much gave up on waiting for a fix to the unwanted deformations of the surfaces as a result of direct editing of polysurfaces via the Gumball. :slight_smile: I’m forced to rely on the fully manual editing, surface by surface.

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i will eventually yield like you but in the meantime i am pissed. mainly by the approach that it is like it is cope with that not acknowleding it is clearly wrong.

It’s like, you’ve been suing Rhino since 2020 and you’ve suddenly noticed it’s not literally Solidworks.