Sweep 1- twist

Grasshopper
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1

Hello,
I have this problem where I tried to make a sweep 1 with differents curves (section) and it seems to work but I have twist between curves. How can I fix that?

Thank you in advance for your help.

Screenshot 2026-04-03 231616
Screenshot 2026-04-03 2316161817×754 222 KB

here is the systeminfo :

Rhino 8 SR29 2026-3-4 (Rhino 8, 8.29.26063.11001, Git hash:master @ bbd126f84fcdaf7a974615b7c9f4f8667571c147)
License type: Educational, build 2026-03-04
License details: Cloud Zoo

Windows 11 (10.0.26200 SR0.0) or greater (Physical RAM: 16GB)
.NET 8.0.22

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

Hybrid graphics configuration.
Primary display: Intel(R) Arcℱ Graphics (Intel) Memory: 2GB, Driver date: 10-22-2025 (M-D-Y).

Integrated graphics device with 4 adapter port(s)

  • Laptop lid is possibly closed
  • Windows Main Display attached to adapter port 1
    Primary OpenGL: NVIDIA GeForce RTX 4070 Laptop GPU (NVidia) Memory: 8GB, Driver date: 11-18-2025 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 581.95

Integrated accelerated graphics device with 4 adapter port(s)

  • Secondary monitor is laptop’s integrated screen or built-in port

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: 11-18-2025
Driver Version: 32.0.15.8195
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 8188 MB

Rhino plugins that do not ship with Rhino
C:\Program Files\Enscape\Enscape.Rhino.Plugin-net48\Enscape.Rhino8.Plugin.dll “Enscape.Rhino8.Plugin” 4.1.1.35
C:\ProgramData\McNeel\Rhinoceros\8.0\Plug-ins\Datasmith Rhino Exporter (d1fdc795-b334-4933-b680-088119cdc6bb)\DatasmithRhino8.rhp “Datasmith Exporter” 5.6.1.0

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 8\Plug-ins\Commands.rhp “Commands” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 8\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\RhinoRender.rhp “Legacy Rhino Render”
C:\Program Files\Rhino 8\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 8\Plug-ins\MeshCommands.rhp “MeshCommands” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\IronPython\RhinoDLR_Python.rhp “IronPython” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\RhinoCycles.rhp “RhinoCycles” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\Grasshopper\GrasshopperPlugin.rhp “Grasshopper” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 8.29.26063.11001
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\Calc.rhp “Calc”
C:\Program Files\Rhino 8\Plug-ins\SectionTools.rhp “SectionTools”

2

Could you please share this .gh file? Thank you.

3

Thank you for your reply.
Please, attached find the files. It’s a parametric bench that we are building. I have refereced points in rhino that I aslo put the file in there.

I am grateful for your help.

parametric bench referenced points -.3dm (67.3 KB)

parametric bench -sweep1.gh (12.2 KB)

4

Hi @Michelle_Zephyr,

One of your profiles was inconsistent orientation-wise, so I rotated it and then ran the SimplifyCrv command in Rhino just in case. After that, making the seams consistent across all sections gives this:
parametric bench -sweep1b.gh (44.4 KB)

image
image1920×985 153 KB

5

Thank you for your reply.
Actually that is the desire form that I aimed to have.
Loft was the command used without grasshopper. But in grasshopper I tried sweep and the form twist.

Screenshot 2026-04-04 144113
Screenshot 2026-04-04 1441131399×754 99.4 KB

1 Like
6

Do you think there is a way to make the twist disappear? I would love to keep the ‘wave’ shape, if possible. Thank you in advance for your help.

1 Like
7

Yes—the ‘seam adjustment’ I showed you takes care of that. Did you try it?

I was just mistaken on rotating your profile. If you apply the same adjustment to what you had, you get this:

image
image1867×701 128 KB

Notes:
First, be aware that by having a profile that faces opposite you’ll still get a surface that self intersects*—this shows up on your manual loft as well:

image
image688×750 75.5 KB

A quick ‘straight’ sweep using the same profiles helps you see this:
image
image830×754 40.1 KB

Second, it helps if in Rhino you change your ‘mesh’ options to higher density/quality—and in GH you want to make your meshing ‘high quality’ as well.

*An alternative could be tweening curves between your sweep profiles so you account for the change in orientation/surface transition, but results might be weird.

1 Like
8

Thank you so much. Before your reply, I separated the curved bench base and the wavy part (using the Loft command in Grasshopper to simplify the model). It is less fully parametric, but it worked. I haven’t tried your recommendation yet, but I definitely will!
Thank you again for your time.

1 Like