Hi, I am having trouble with how a surface is being displayed after trimming:
Before trim
After trim
Clicking the surface shows the correct geometry outline, but the surface itself is displayed strangely in all display modes. What is happening here? Is there a way to resolve this? I have tried this in both Rhino 6 and Rhino 7, it is the same.
Hi @rjv
Welcome to the forum 
Two things to do:
A) post the offending surface and the trim curve (select the two and Export as a Rhino file) here on the forum. It’s impossible to tell from just the screen grabs what is going on. You can drag’n’drop the file onto the reply window or click the small up arrow in the row of icons at the top of the message window to upload a file.
B) Run the command SysInfo in Rhino and post the resulting text here as well. That’ll give people a place to start
HTH, Jakob
Hi @Normand,
Thanks for the reply. Here’s the file:
trimsurface.3dm (410.7 KB)
Also the sysinfo:
Rhino 7 SR12 2021-11-9 (Rhino 7, 7.12.21313.06341, Git hash:master @ 5590153808223b57a9f41516a969fd949aa81bff)
License type: Commercial, build 2021-11-09
License details: Cloud Zoo
Windows 10.0.19041 SR0.0 or greater (Physical RAM: 32Gb)
Computer platform: LAPTOP - Plugged in [98% battery remaining]
Non-hybrid graphics configuration.
Primary display and OpenGL: NVIDIA GeForce RTX 2070 (NVidia) Memory: 8GB, Driver date: 5-6-2021 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 462.59
> Integrated accelerated 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
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: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: High
Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 5-6-2021
Driver Version: 27.21.14.6259
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
C:\Program Files\SimLab\Plugins\SimLab 3D PDF From Rhino 6\plugins\SimLabPDFExporter.rhp “SimLab PDF Exporter”
Rhino plugins that ship with Rhino
C:\Program Files\Rhino 7\Plug-ins\Commands.rhp “Commands” 7.12.21313.6341
C:\Program Files\Rhino 7\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 7\Plug-ins\RPC.rhp “RPC”
C:\Program Files\Rhino 7\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 7.12.21313.6341
C:\Program Files\Rhino 7\Plug-ins\RhinoRender.rhp “Legacy Rhino Render”
C:\Program Files\Rhino 7\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 7.12.21313.6341
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” 7.12.21313.6341
C:\Program Files\Rhino 7\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 7.12.21313.6341
C:\Program Files\Rhino 7\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 7\Plug-ins\Displacement.rhp “Displacement”
Hi @rjv
I’m not seeing the same thing here, but my guess is that maybe it has to do with the render mesh. Go to Options>Mesh and try setting it to “Smooth and Slower” or go to custom and set everything to 0 except for Max. aspect ration=3 and Max. distance, edge to surface=0.1.
On a different note, modeliing something this big (120 meters long) in milimeters with a tolerance of 0.001mm could very easily lead to trouble downstream. You could consider easing up on the tolerance a little
HTH, Jakob
PS And you graphics card driver could do with an update!
Hi @Normand, that is strange. Should I trim it on my end first then send the surface file to you?
I have tried adjusting the mesh options because I saw that as a proposed solution on another thread about trimmed surfaces, but it did not work for me.
Noted on the tolerance, however I seem to have other problems with a bigger tolerance (eg unable to trim, etc)
I have tried trimming the surface a little higher up, it has a similar issue
Hi Rajiv -
I see that here in your file:
As Jakob said, changing the mesh settings will clear this up:
Apart from that, the layer name suggests that this is created from an imported IGES file and you might not have a lot of control over the origin of this polysurface… but looking at the dense network of isocurves, you should be able to significantly simplify this. Also, exploding that polysurface into its 4 surfaces reveals one that is almost collapsed to a line:
That’s still within document tolerances but probably shouldn’t be necessary for an object of this size.
Finally:
There shouldn’t be any reason for not using the current 7.25 version.
-wim
@wim thank you, those mesh settings work for me. The problem still persists when I zoom in further at the tip, but this is sufficient for me as I wouldn’t normally need to zoom that close.
For your info, the surface was created in Rhino using Sweep. The bottom horizontal edge was created using a curve from an imported IGES surface from NAPA.
With regards to Rhino version and graphics driver, unfortunately getting either updated in my company is too much of a hassle; I would rather not update unless absolutely necessary for my work.
