Geometry.SubD.CreateFromLoft not being affected by addCreases parameter

I’m trying to do a SubDLoft in grasshopper using Python as there is no grasshopper command for that. I have 3 curves I’m using for the loft and I’m baking those 3 lines in Rhino and using the SubDLoft command for comparison. The top shape is created from SubDLoft with Add Corners and Add creases, the top one is created with Add Cornes and WITHOUT Add Creases. The middle one is from the code below, which also adds corners and add creases. Changing the creases boolean parameter does not take any effect and the shape always looks like the SubDLoft without add creases.


import rhinoscriptsyntax as rs
import scriptcontext as sc
import Rhino as rc

a = rc.Geometry.SubD.CreateFromLoft(x, False, True, True, 1)




Rhino 7 SR27 2023-2-1 (Rhino 7, 7.27.23032.13001, Git hash:master @ 4a0030c0d354560df03764f4f49ecc5d119e5118)
License type: Evaluation, build 2023-02-01
License details: Cloud Zoo
Expires on: 2023-05-26

Windows 10 (10.0.19044 SR0.0) or greater (Physical RAM: 64Gb)

Computer platform: DESKTOP

Standard graphics configuration.
Primary display and OpenGL: NVIDIA GeForce GTX 1060 6GB (NVidia) Memory: 6GB, Driver date: 7-21-2022 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 516.94
> 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: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: High

Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 7-21-2022
Driver Version:
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 6 GB

Rhino plugins that do not ship with Rhino

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 7\Plug-ins\Commands.rhp “Commands” 7.27.23032.13001
C:\Program Files\Rhino 7\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 7\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 7.27.23032.13001
C:\Program Files\Rhino 7\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 7.27.23032.13001
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\IronPython\RhinoDLR_Python.rhp “IronPython” 7.27.23032.13001
C:\Program Files\Rhino 7\Plug-ins\RhinoCycles.rhp “RhinoCycles” 7.27.23032.13001
C:\Program Files\Rhino 7\Plug-ins\Grasshopper\GrasshopperPlugin.rhp “Grasshopper” 7.27.23032.13001
C:\Program Files\Rhino 7\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 7.27.23032.13001
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\SolidTools.rhp “SolidTools”
C:\Program Files\Rhino 7\Plug-ins\Squish.rhp “Squish”
C:\Program Files\Rhino 7\Plug-ins\RhinoRender.rhp “Legacy Rhino Render”

The result is also different if you force the crease on all edges after the SubDLoft in Grasshopper, or if you check the Crease option in Rhino - which is more like the Interpolate option of SubD From Mesh.

Also the creases at mesh edges option does not seem to work in SubD From Mesh. Or is the mesh invalid ?

And why is the reference to object lost in the second SubDEdges when switching false to true ?..

Hope these examples help !

SubDLoft (17.1 KB)

I’m not sure if I was clear, but was not that the reference is lost, it seems that setting crease to true is not taking effect. This is the result of SubDEdges with Creased set to true. When doing outside grasshopper the effect is the round curves meet the bottom curve and I get a nice rounded shape. With creased off, you can see the round curve is above the bollow and in the front of my hull shape I get some weird shape.

Perfectly. I do have the same issue as you, and some more I encountered experiencing with your case.

1 Like

If this is a confirmed bug, what would be required from me, do I need to open a support ticket with Rhino or is this forum enough? I’m evaluating Rhino so not sure how this works as this is the first support I ever need for this.

This thread should be enough to get the attention from someone at McNeel to check this issue. I don’t know who to tag specifically, maybe @Gijs or @wim ?

Hi @Eduardo_Piva,

If Rhino’s SubDLoft command is producing different results than the SubD.CreateFromLoft, then please post your input curves, along with any other details, source code, etc., that will help us reproduce the issue you are seeing.


– Dale