Building a segmented arc.

Hey everyone!

I cant seem to build a particular structure in GH.

I'm trying to make an adjustable segmented arc. The arc is to be build between two control points based on a set length and number of segments.

I understand this is more of a general geometry question, but I just hope that there is some tool/logic/plugin in GH that I'm just not aware of and that could be helpful.

Any suggestions?

Replies to This Discussion

Permalink Reply by johnnyUtah05 on July 12, 2015 at 9:03pm

Hi Stepan,

This may be too simple, but is this what you are after?

Permalink Reply by Stepan Drunks on July 13, 2015 at 9:18am

Hi Erik, It's not exactly what I want to achieve. It is vital for me to have arc segments maintain constant length no matter what distance between the control points is (unless it is greater than the length of all the segments combined).

Permalink Reply by David Rutten on July 13, 2015 at 10:21am

I thought the equations looked do-able, but either I was wrong or I made a mistake. Even Mathematica can't seem to figure out how to solve for x on this one.

I attached a Galapagos solution, not ideal. It can be sped up significantly using some clever C# code which knows how to sample the arc, so if you need a fast solution let me know.

Attachments:

arc fitter.gh, 10 KB

Permalink Reply by Stepan Drunks on July 14, 2015 at 4:47am

That's just what I needed!
I knew there was some tricky way to approach this problem. Turns out all I needed was Galapagos. Thanks for introducing me to it, and for the algorithm too.

As for the speed — it does not really matter for my purposes.

Permalink Reply by Nik Willmore on July 14, 2015 at 7:17am

The Kangaroo physics Equalize Angles force with proper spring force/damping setting to avoid overshoot can do it too once fed a workable precursor to modify:

Just don't move the length slider too fast or you can still get overshoot and thus chaos:

Attachments: