It’s ok if the component doesn’t run if the point is not in the plane of the circle, but it only happens if it’s in a positive direction from the normal direction of the plane, in a negative direction it does something strange. private void RunScript(Circle circle, Point3d point, ref objec…

Could be related to tolerance: Recently there was a post: [image] Can this be combined into a closed BREP? Grasshopper Ah sorry i missed the grasshopper part. If you absolutely have to join them in grasshopper and can’t use the native Rhino _Join command before referenci…

I don’t think so. It’s not a tolerance-dependent algorithm. It has an exact solution. And it’s also not related to whether it changes its behavior above or below the plane. It looks like a bug, or at least a partially handled invalid situation.

the point which touches the circle is dependent on tolerance, isn’t it?

No, it’s not done by making intersections, but by using trigonometry.

I believe all modeling software is highly dependent on the tolerance accepted in the approximation algorithms it has. Trigonometry or not, the values are approximated to a certain floating number. truncated at some point leading to errors. A slight move of the point on a circle (depending on roundin…

As I understand it, the problems relating to tolerances are the problems relating to limits, mathematically speaking. Computationally you can’t approximate a solution infinitesimally, so you need a tolerance to set a threshold that makes the limit reasonable. Intersections need this to set a resolut…

I don’t know what is the code behind that component. If you project the point on the plane of the circle before hooking it to the tangent line component it works fine. There’s definitely sometging wrong there, though. PS: Trigonometry is also prone to errors due to precision: http://www.extremeo…

[image] ivelin.peychev: Trigonometry is also prone to errors due to precision Well, good to remember that, but a difference in the eighth decimal place wasn’t going to change anything here.

[2020-04-02 19_12_30-Window] Seems like it is only evaluating the distance from the center and the radius of the circle. The out-of-plane point is at the same distance than the intersection of the found tangents…

Tangent Lines strange behaviour

Grasshopper

ivelin.peychev (IVELIN PEYCHEV) April 2, 2020, 3:46pm 2

Could be related to tolerance:

Recently there was a post:

Topic		Replies	Views
_Circle _Tangent _FromFirstPoint Geometric Challenge (Bug ?) Rhino for Windows rhinoformac	12	1215	November 24, 2016
Best way to test if two curves are tangent? Grasshopper windows	18	2052	July 25, 2022
BUG : "Line Tangent Two Curves" not robust Rhino for Windows	3	481	August 19, 2020
Curve\|Plane Intersection missing intersections Bug? Grasshopper Developer	4	883	March 4, 2025
Arc tan / tan / radius fail Rhino windows	18	407	January 29, 2026

Tangent Lines strange behaviour

Related topics