Drawing a curve on surface is sometimes very wonky

Rhino Rhino for Windows
1

Why is InterpcrvOnSrf creating these wonky red lines? Is there a better command for drawing a curve on surface?

image
image754×501 59.5 KB

I tried to add more points to guide the curve, but they just became more distorted.

COS-wonkiness.3dm (271.2 KB)

(Just for clarification, the result I expected from COS drawing is what you get if you place a straight line at those end points and pull them to the surface…)

2

Hello - ShortPath may get you what you need here if the input is two points.

Here’s a version I like better because of the preview
ShortPathEx.py (2.7 KB)

To use the Python script use RunPythonScript, or a macro:

_-RunPythonScript "Full path to py file inside double-quotes"

Also - CurveOnSurface | Food4Rhino

-Pascal

2 Likes
3

Thank you for the tips!

But two points:

  1. Oh my dear lord, why aren’t both of those things built into Rhino? :laughing:
  2. In what scenario is the result I posted from my file desired behavior?

EDIT: Oh, that poor 6+ year old user made plug-in does not work on polysurfaces (but then again, not many McNeel commands do either).

4

So 8 months later I’m continuing this little project… and I’ve made a simpler example:

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image608×502 41.4 KB

I still don’t see any scenario where the red line is the desired result. To me, this is a bug.

COS-wonkiness-2.3dm (192.5 KB)