Issues with extend crv

I have trouble with extendsrf and extendcrv, but let’s talk about extendcrv for now. In the example attached, I have an original curve that I can extend (type=smooth) only about 2x. If I rebuild it to simplify it, extend is still very limited. Bug or bug?

Even if I rebuild this curve with 2 pts and degree 1 (straight line) I still can’t extend it much at all.
cant extend beyond 9.7 001.3dm (61.2 KB)

Hi Peter - are you extending by typed length or dynamically in the viewport? Either way works fine here in our latest - can you run SystemInfo in Rhino and post the results? Incidentally your curve simplifies to a line (SimplifyCrv)


I’m doing dynamic, not typing a number.

Rhino 7 SR20 2022-7-12 (Rhino 7, 7.20.22193.09001, Git hash:master @ 9b19bfdb8c343dd6fa8df3514068defd72273d6f)
License type: Commercial, build 2022-07-12
License details: Cloud Zoo

Windows 10 (10.0.19044 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: 1-28-2022 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 511.65
> Accelerated graphics device with 4 adapter port(s)
- Windows Main Display attached to adapter port #0
- Secondary monitor attached to adapter port #1

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: 1-28-2022
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\phcre\AppData\Roaming\McNeel\Rhinoceros\packages\7.0\NVIDIADenoiser\0.4.2\NVIDIADenoiser.Windows.rhp “NVIDIADenoiser.Windows”

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 7\Plug-ins\Commands.rhp “Commands” 7.20.22193.9001
C:\Program Files\Rhino 7\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 7\Plug-ins\RhinoScript.rhp “RhinoScript”
C:\Program Files\Rhino 7\Plug-ins\RPC.rhp “RPC”
C:\Program Files\Rhino 7\Plug-ins\AnimationTools.rhp “AnimationTools”
C:\Program Files\Rhino 7\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 7.20.22193.9001
C:\Program Files\Rhino 7\Plug-ins\RhinoRender.rhp “Legacy Rhino Render”
C:\Program Files\Rhino 7\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 7.20.22193.9001
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” 7.20.22193.9001
C:\Program Files\Rhino 7\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 7.20.22193.9001
C:\Program Files\Rhino 7\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 7\Plug-ins\Displacement.rhp “Displacement”

Hm- I tried with 7.20 and that also works just fine - working in your big viewport.