Mesh.CreateFromCurvePipe bugs

Rhino Developer
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1

Hi @dale,

i’ve collected some curves from todays trials to use Mesh.CreateFromCurvePipe method. It has a high failure rate even with the simplest curves. On closed curves, the ends to not match. Almost all curves i’ve tried resulted in a mesh with naked edges which cannot be welded in order to obtain a closed pipe (with open end caps).

Even _AlignVertices was not able to fix the pipes prior welding. Please find my example script and file below.

MeshCreateFromCurvePipe.3dm (109.8 KB)
MeshCreateFromCurvePipe.py (1.1 KB)

Btw. the accuracy argument in the docs needs some love (eg. range of possible values). Ramping this value up can make some heavy meshes…

thank you,
c.

2

Hi @clement,

Seems pretty flawless here:

image
image751×419 96.6 KB

Am I missing something?

– Dale

3

Hi @dale, please run _ShowEdges on the resulting meshes. I have this:

grafik
grafik1494×986 136 KB

Closed curves result in this:

grafik
grafik743×492 39.2 KB

I don’t understand that naked seam placement:

grafik
grafik743×492 99.4 KB

A (planar) rectangle looks like this:

grafik
grafik743×492 89.5 KB

do you have different results or changed something in the example script maybe ?

thanks,
c.

4

Hi @clement,

If you just use Rhino (Properties > Curve Piping) and then extract the render mesh, do you get the same junk?

– Dale

5

Hi @dale, yes. The naked edges are identical. Is the mesh pipe supposed to have a seam along the curve at all ? There is none for the knot like curve, only at start / end. But there is one for other closed curves…

btw. use ShowEdges and compare "All edges " and “Naked edges”:

grafik
grafik1494×986 143 KB

grafik
grafik1494×986 136 KB

_
c.

6

Hi @clement,

For now, use Brep.CreatePipe and then mesh the results if you need it.

I don’t know a whole lot about curve piping. But I’ll open a ticket s a developer can investigate.

https://mcneel.myjetbrains.com/youtrack/issue/RH-86321

Thanks,

– Dale

2 Likes
7

Hi @dale, ok thanks.

_
c.