How do I remove one branch from JoinCrv result before feeding into Boundary Surfaces?

Hi, so I’m pretty new to Grasshopper, I was making a curved stairwell so I first made outlines for every step. I merged the four edges together (left edge, right edge, connecting widths) using JoinCrv but I’m left with a single line at the end because it doesn’t have any other geometry to connect to.

This is the far end of my Grasshopper set-up, and one branch says Line-like curve at the end of the panel connected to the Join component.

For reference, here’s the result. It’s actually fine, but the extra invisible line at the end will cause problems if I try to use the BoundarySrf result for other components.

How do I remove the last line/branch from the JoinCrv panel that says “Line-like Curve”?

Also if anyone’s kind enough how do I move them sequentially upwards for stair riser height? Thank you!

Here’s my GH file: (16.9 KB)

You didn’t internalize your curves.

By the way, renaming standard components is counter-productive in my experience. Better to rename outputs instead of the components.

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Oh. I still wasn’t familiar with internalization. How does it work?

And noted on the renaming. Thank you!

Or post the related Rhino .3dm file, preferably saved as R6 format.

stairs R6.3dm (172.8 KB)

Here, sir! Thank you!

One curve is still missing:

Oh, the curve attributed there is the one horizontal line there at the base of the main curve. My bad. (14.1 KB)

Here’s another way… (9.4 KB)

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I figured that out. It’s easy to see why this happens. I used an expedient shortcut to get around it.

stairs_2021_Jul2a (10.4 KB)

P.S. This version has the curves internalized. (10.9 KB)

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Thank you! Will use this as another iteration.

Thank you sir! Was just studying the first one you sent me. Thank you! I’ll marked this solved.

Unfortunately, there is a problem. The steps are out of sequence after SrfSplit so I had to sort them (white group). (17.3 KB)

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Yet another method, closer to your original approach and question. This doesn’t use SrfSplit so doesn’t require Sort Along Curve, though it looks more complex, eh? One simplification is to use Divide Curve instead of DivLength. (29.6 KB)

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Thank you for all your replies, master! I’ll study the latest one too.

Foolish of me not to add Prune Tree to your original code! (yellow group) (18.3 KB)

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Whoah. Info overload :laughing: ! Thank you! Will study these as well.

Version ‘d’ is the simplest answer to your question in the thread title:

How do I remove one branch from JoinCrv result before feeding into Boundary Surfaces?

:man_facepalming: Prune to keep only the branches with four curves and ignore the branch with only one curve.

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Yeah I figured when I opened it. Nonetheless, the additional workarounds taught me a lot too!

This was a classic example of jumping to a conclusion (“a shortcut”) that painted myself into a corner, requiring “extraordinary measures” (sorting) to get out of it. Software is like that, hence the many revisions. Sorry about the info overload.

This is my final offer, I promise! :wink: Shortest List instead of Prune Tree. (22.9 KB)

Simpler? Curves are internalized.

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