Hi everyone, I’m trying to fit a spline into a polyarc given a set of points and a tolerance. In particular, my constrains are: Tolerance expressed as the maximum distance between the original curve and the fitted one(which should be an input) The lines that compose the fitted curve should start …

[image] matteo.dopudi: via some coded script Indeed: although there’s some stuff available as native components the general case for this requires code - let’s say in a way remotely “similar” to this: [image] C# Cubic Spline Interpolation This article presents a from-scratch imp…

Hi Peter, thanks for the quick reply! Yeah somehow the logic should be similar to the papers you attached even if the constrains are a bit different. I’m not very good with C#, I can read the code but not quite write it. Actually it is the first time I can’t manage to solve a problem only using Gr…

[image] matteo.dopudi: only using Grasshopper Well … let’s wait for some good Samaritan who could handle this via native GH stuff … and if not coding could save the queen.

Ahaha I’ve tried for the last few days but the only thing I got is a very long definition that goes nowhere. The code was working until I got the limitation on the arches (the fact that they have to lay at least on three points) which complicates a lot the process in my opinion

Well … you should post the stuff that you have insofar (case: native components) in order to allow people to skip re-inventing the wheel. Other than that: what’s the purpose? road/bridge/tunnel design? beam design? facade design? truss spine design? Other than that: is this topology posted represe…

So I’m uploading the code so far… it is not very efficient but that’s the best I came up with. Also there are components from BullAnt and Metahopper that I couldn’t manage to replace. Second question: The purpose is aluminium fabrication, the spline is an architectural line that, in order to be fab…

I don’t have these add-ons … but … wait for a second: Is it possible that the problem of yours is the inverse one? I.e. given a nurbs do the best approximation by a collection of arcs (plus maybe some line segments). If so the thread title is wrong: should be “best planar nurbs approximation via ar…

Yes that is definitely what I meant… sorry if I have not been clear. I’m changing the title Given a NURBS find the best approximation with arches and lines. Your tool seems quite similar to the BullAnt component but in both cases it seems to me that the problem is that is not possible to take into…

Well … the C# captured pays very little attention to absolute accuracy and fixed points since there’s no meaning for doing that (it just “approximates” an indicative guide rail via some heavy stuff - within AEC level of accuracy, so to speak). On the other hand … the min length of a given arc is th…

Indeed the length of the arc is a very important variable to take into account. Maximising the length of the segments would be quite important. There a lot of constrains in this analysis…

Best planar nurbs approximation via arcs and lines

Grasshopper

AndersDeleuran October 28, 2024, 10:08am 16

You might also try this native Rhino method:

Topic		Replies	Views
A fast way to approximate a Bezier- or Nurbsspline to an array of points Rhino Developer	20	6761	June 21, 2019
Approximate Curve with standard Library of arcs and straight segments Grasshopper windows	11	541	June 28, 2025
Nasty Nurb - When is a straight line not a straight line? Rhino Developer windows	15	817	November 20, 2023
Nurbs curve with minimal control points GH for Mac grasshopper	6	902	February 25, 2020
Reverse of Curve Interpolation Rhino Developer windows	7	874	July 20, 2022

Best planar nurbs approximation via arcs and lines

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