select / idenfity connected geometry

Hey everyone,

is there a way of doing something equivalent to "fastsel" in autocad, in Grasshopper? This is what I mean: http://www.cad-addict.com/2009/07/autocad-select-all-connected-geom...

I have a total "bird's nest" of lines in 3D (not originally created in Grasshopper) which I eventually want to 3D print - but it's not a quick or easy job to tell which of the lines are connected to each other and which are floating and will just fall on the floor when 3D printed. Would be super if there was a way of doing this in Grasshopper, but I can't think of a simple workaround. Maybe there isn't one!

I should add - sometimes he lines intersect end to end, sometimes just somewhere along their lengths, sometimes not at all - I want to end up with the "chunks" that are connected.

Thanks in advance.

Replies to This Discussion

Permalink Reply by Danny Boyes on April 7, 2016 at 8:15am

This would give you a list of curves that connect to at least one other curve:

Multiple Curves and Create Set

Permalink Reply by Emma-Kate Matthews on April 7, 2016 at 8:27am

That's a good first step for getting rid of the curves which are totally floating, but... then I want to be able to isolate each of the chunks that are connected, so that I could bake them & connect them up. Is there a way to partition the list of connected curves, so the chunks could be split out again & baked as separate groups?

Permalink Reply by peter fotiadis on April 8, 2016 at 12:42am

What you need is to understand how connectivity trees work (using Starling on that entry-level demo, in order to avoid some C# that rather could puzzle you more).

Note: NOT all available connectivity "possibilities" are used: try to get the gist of the whole approach and make any "query" you want.

Notify if you need more elaborated ways to viz (or "group") related items (for instance using text-dots reporting length etc etc)

Attachments:

Connectivity_trees_entry_level_demo_V1.gh, 127 KB

Permalink Reply by Emma-Kate Matthews on April 8, 2016 at 12:48pm

Cool, thanks I'll have a play with this - on first attempts, it seems slow with anything over about 100 lines (I have nearing 10,000 in total...) but maybe that's because it's always creating a pipe and a sphere for each curve. I'll have a mess around with it.

Permalink Reply by peter fotiadis on April 8, 2016 at 11:50pm

Indeed that's the reason for the slow response (but that was just a simple demo).

Remove/Disable the "viz" content as soon as you feel comfortable with connectivity trees.

Permalink Reply by Pieter Segeren on April 8, 2016 at 3:53am

Hi Emma-Kate,

here you can find a script by David Stasiuk that works great for this.
I was thinking that if you give your lines a thickness first, there may be more pieces that are/get connected already...

Permalink Reply by Emma-Kate Matthews on April 8, 2016 at 12:49pm

Great, this looks very useful! Thanks!

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