algorithmic modeling for Rhino

Hi everyone!

Im trying to make a spiral staircase and Ive hit a small bump.

I managed to create the Inner and outer spiral and the resulting steps but now I want the bottom of the stair to be sleek.

Normally I would use the Line at the bottom of the steps and Sweep2 but in this case the resulting surface will cut through the constructed steps. How could I do this?

And my other question is where the big Brep under the first step comes from? I have no Idea how it came but it was constructed by the Srf4Point.


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What do you mean by "to be sleek"?

The big brep under the first step is an off-by-one error.  If you examine the surfaces coming from the 'Srf4Pt' component, you will notice that they start at the bottom and go up; that big unwanted brep at the bottom is #24, not #0.  You can eliminate it by setting the 'Wrap (W)' input of 'Shift' (Shift List) to false, though that really just hides the problem.  'Shift' will have only 23 lines in its output list but 'Move' still has 24, so you need to remove one of them by adding 'Shift' there too.

The 'Tree/List Viewer' tool I left in the code is very helpful for this kind of thing.


What I mean with sleek is that when looking up at the bottom of the stairs you wont see the individual steps but that its smooth. Like here

Thanks a lot for your help! Makes sense now.

This is one way to make it "sleek" - there is a gap on the side that needs to be filled... several ways to fix that ('Brep Edges' comes to mind).  I'll leave that to you.






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