Convex hull failure

Attached a GH file with two data sets for the convex hull component. One set works the other set fails for me. What may I be missing here?


convex hull failure.gh (12.4 KB)

No problem here

Update Ngon Plugin !

missing

What does the error message say on the failed component?

Standard GH Convex Hull works for both sets of points, revealing a triangle in both cases.

Why not use PLine (Polyline) to get the triangle from the points?

Sorry for not including that, the error message reads:

I use the convex hull to orient linked 3D structures properly on the XY plane. Usually the objects are 3D, the 2D ones are the exceptions. For the planar objects I nudge one vertex as a hack to make it 3D for the convex hull component.

I’ll get the plugin update and will report the results.

Here is an example of a set of objects placed on a plane using the convex hull script:

Many more of them here.
GH rocks for me!

Standard GH component Convex Hull doesn’t work for you?

That did the trick!!!

Thank you for the quick responses!

It failed in the initial example. I updated the plugin and it now works as expected.

The standard GH component works fine with both sets of points you posted. How about posting the set of points that causes it to fail?

I cried victory too soon :frowning:

Here a screenshot with the two data sets and the error message:


GH file with point attached.

convex hull failure 2.gh (7.8 KB)

Do you understand what I’m saying about the standard GH Convex Hull component vs. the plugin?

Works fine for me. The two sets of points are so close together that the results are almost identical.


convex hull failure 2_2023Jan14a.gh (8.4 KB)

My bad, now I do. The standard Convex Hull component works for me as well.
I used a different Convex Hull component for its Mesh output.

wow… :man_facepalming: 4th time saying it is a charm, I guess.

I’m sorry for not being clear. What I try to say is the standard component works with the data sets I provided. However, I need a 3D mesh hull output. For that I used the plugin hull component that fails.

Hello
Not on my pc so I can’t test your file. But if you want a mesh it means you want a 3d convex hull. So points must not me on a plane. If it fails again you could also cull near points.

Laurent, that was helpful!

Just for this record, in my large data set I filter the sparse planar instances and slightly offset 1 vertex to force non-planarity for the 3D Convex Hull component. Slightly altering 3 vertices eliminated the failures. There may be some edge or tolerance issues for nearly-planar vertex sets with the 3D Convex Hull plugin component.

With this component I have this message

In order to move slightly the points you could move all the points. Here I move on Z depending on X. Then I move back the points. It seems to work. But if X is big it could be better to use Sin(x)*0.001 instead of x * 0.001.
convex hull failure 2LD.gh (11.4 KB)

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