Trim Self Intersecting Pieces of Curve Away?

Hi everyone!

I am having trouble removing the self intersecting bit of my some curves...

I found the intersection, shatter at those self intersecting points, but then I need to cull these pieces and join the curve back together. Right now I am using a cull pattern, culling away the smallest pieces, which coincidentally are the self intersecting ones. But sometimes a smaller non intersecting piece is trimmed.

Additionally, when other date is inputted, the slider that controls the length to cull is not always in an optimal value, so it needs to be readjusted manually...

Thanks in advance for any help,

Shynn.

Attachments:

Trim Self Intersecting Piece.gh, 33 KB

Replies to This Discussion

Permalink Reply by Joseph Oster on November 12, 2017 at 8:31pm

Here's something... The yellow group works on just one self-intersecting curve. I had to put it in the Anemone loop because I couldn't think of another way to determine if 'Srf CP (D)' was zero (less than 0.0001) for any of the 'Shatter' curve midpoints - other than 'Flip/Sort/List Item', which won't work with multiple curves.

Attachments:

SelfIntersectingCrv_2017Nov12a.gh, 50 KB

Permalink Reply by Vongsawat Wongkijjalerd on November 12, 2017 at 11:41pm

Hmm, here's an alternate solution perhaps; using Shortest Walk?

If you have complex self-intersections it might not work how you want it to though(or might?)
But if its simple, ie. the culled intersecting pieces don't themselves overlap, then it should work well enough.

Permalink Reply by Joseph Oster on November 13, 2017 at 5:17am

That occurred to me too but I don't have the plugin. Since you apparently do, why not try it?

Permalink Reply by ShynnSup on November 13, 2017 at 6:59am

Thank you both,

You really love anemone dont you Joseph? haha thank you.

Super smart vongsawat! Works perfeclty, thank you! Will use this solution.

Permalink Reply by Joseph Oster on November 13, 2017 at 7:12am

I studied several ways to do this without using 'Boundary' or Anemone but couldn't see one, maybe I missed it? I'd say it's a very safe bet that Shortest Walk uses iteration and/or recursion internally.

Permalink Reply by Vongsawat Wongkijjalerd on November 13, 2017 at 9:54am

yea, I just don't like using Anemone much :P the logic tends to mess with real-time stuff..
Last time I tried to solve an intersection problem like this it ballooned horribly and I just had to walk away. Inspiration suddenly struck and went and downloaded Shortest Walk to test it out :P sadly complex intersections will 'short-circuit' the whole thing in a sense.

Permalink Reply by Joseph Oster on November 13, 2017 at 11:11am

I just installed and tried Shortest Walk; it seems to work well in this case, though I didn't push the model's parameter values to test all possible self-intersections.

One thing to note is an issue I dealt with inside the Anemone loop; if there are no self-intersections, I would think you want the original curve instead of the null value returned by this group on 'ShortWalk W' output. The 'Stream Filter' I used to do that won't work on a data tree.

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