Extract center lines

Hello there fellow users.

I'm having a hard time by drawing centerlines "manually" [via OSNAP center] to a set of cooling pipes. Some times they can be very difficult to draw.

If there are tools like "Sweep" and "Pipe" is there any tool that makes the inverse. I have lots of cylinders and pipes and I use some command and extract the center lines in Rhino.

Does anyone knows any way to do this?

Best Regards
André

Attachments:

Capturar.PNG, 11 KB
tool.jpg, 30 KB

Replies to This Discussion

Permalink Reply by Hyungsoo Kim on November 5, 2017 at 12:03am

Hi.

It may not work in all cases, but probably helpful to refer to this definition.

Attachments:

ExtractCenterLine_re.gh, 48 KB

Permalink Reply by André on November 5, 2017 at 9:59am

Awesome

I'm gonna give a try

Thanks a lot.

Best Regards

André

Permalink Reply by André on November 8, 2017 at 4:52am

Well i gave it a try but i'm having trouble, the output gives me this wierd looking curve.

P.S: I'm a beginner in Grasshopper, but you got a module at the right part of the image next to the snatch, and when i open the file i can´t find it

Best Regards

Attachments:

snap2.jpg, 46 KB

Permalink Reply by Piotr on November 8, 2017 at 5:22am

Hi Can you post a 3dm file so I can play wit it?

Permalink Reply by André on November 8, 2017 at 5:34am

Yes here it goes.
The main goal is to make a path were the cooling liquid passes.
I can do this manually by extracting the center of the cylinders and make lines, then I make trim and join.
If the could only extract a separate line of each tube I will be a great help.

Best Regards

Attachments:

channel.3dm, 831 KB

Permalink Reply by Piotr on November 8, 2017 at 5:46am

Hi Andre

Each surface forms a half of a tube so the results will be doubled.

Are you looking for some universal def. or the one that works only in this case?

Permalink Reply by André on November 8, 2017 at 6:56am

Hi there

I'm looking for a universal one (because I work with lots of formats [.STEP .3DM .IGES....]
If the results are doubled it won't affect the goal, i can select duplicates and erase the ones that are doubled.

Best Regards

Permalink Reply by André on November 10, 2017 at 1:33am

But if you show me the solution for this one. I can work it out.

Best Regards
A

Permalink Reply by Piotr on November 10, 2017 at 2:06am

I was hoping to help you then i was stuck with my own things and left for a few days. I will try to look at it when I'm back home.

Permalink Reply by Pieter Segeren on November 10, 2017 at 3:30am

Hi André, check out Surface.TryGetCylinder method in the sdk.

Permalink Reply by André on November 10, 2017 at 4:58am

Hi there!
The Surface.TryGetCylinder method is a boolean right?

So the output will be True or False not the lines ?

Best Regards
A

Permalink Reply by Pieter Segeren on November 10, 2017 at 6:17am

It returns a Boolean, that's correct. If True, you can get the underlying cylinder (I'll call it 'cyl'), and from that you can create its centerline via
New Line(cyl.Center, cyl.Axis, cyl.TotalHeight)

As Piotr stated there will be duplicates/overlapping lines. I also didn't yet find out how to restrict these lines to the cylindrical surface (or better - brep) piece 'space domain' (sorry I don't know what else to call it~ try it, you'll see what I meant)

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