Extract Curves And Points From Surface


So I created this geometry using Fusion 360 and brought it to Dynamo.

I was hoping to extract curves and points from the surface so I can manipulate the geometry a little more.

Could I get some assistance please?

Can you post your sample SAT file?

I can’t upload attachments because I am a new user :frowning:

Ah! The ban has been lifted!

sample v1.sat (8.8 KB)

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I would recommend trying the MeshToolkit package :wink:


Wow that works great!

Is there a way to control how many points?

Use the maxGridLines input to control the number of points. :grinning:

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Thank you @Ewan_Opie!

Can I bother you a little bit more?
Ultimately, I want to manipulate this with Dynamo.
What are the limits of the manipulations I can do and how would I do so?

Well once points are extracted there should be no limit to what you can do with them.
Are you looking to redefine scale? Stretch geometry? Create framing?
If you could sketch your intention and post a picture, then we can see how best to assist you in your workflow.

Yes more about stretching the geometry.

I was able to manipulate the entire geometry through Geometry.Scale, but that was only through the x,y,z axes.
As the object is of an organic nature, I was hoping to join the ring of points into curves then manipulate each curve.

Does that make sense?

Yep, here is something to get you started with sorting your process.
(Just one method, if the sorting mechanism of the MeshToolkit node for verticies can be explained, there will definately be another way :wink:)
Edit: This method is pretty crude though, I’ll look at a better option Monday.:+1:t2:

SAT Polycurves.dyn (20.6 KB)

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Hi @Ewan_Opie

Thank you for all your help!
I’ve opened your file and I seem to be getting error messages…
Is there a reason why?

What do the errors say?

“No function called PerimeterCurves on a Function could be found”

You may need to turn the preview on for each of the upstream nodes, starting from the Springs.Mesh to polysurface, just to check what has and hasn’t been created. But first, set the Geometry working range to the next value up the list and see if that helps?

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Yea, Springs.Mesh.ToPolysurface isn’t doing anything

Does the MergeAll input have a default input? We may be running different versions of the Springnodes package.

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Ah! Yes the default was false. I made it to true and it runs perfectly :slight_smile:

Thanks again!

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No worries. :slightly_smiling_face: This kind of workflow is intriguing, so I’ll definitely be looking at some optimisation of the curve extraction method on Monday in the office.

EDIT : Well, tuesday but close enough. Here is a much nicer (and faster) workflow.
A maxGridline of 1 will give the perimeter curve, then it’s all go from there. :wink:
SAT Polycurves Revisited.dyn (16.9 KB)

Another possible workflow …
sat.dyn (7.8 KB)

For lines …
sat-lines.dyn (7.1 KB)