Connect a point with several lines to other points

I am currently designing a stadium in grashopper and have come across the following problem. I want to connect two points from a large number of points arranged on a curve to the point on a curve above. there are also several points arranged on the curve above. one point should always be connected to the points below it that are arranged to the left and right of the point. so each point is always connected to two other points via a line (see picture of the static system). can anyone help me?


Screenshot 2024-05-24 194425

Station Bogen (44.8 KB)

I could try to help, but unfortunately, your Grasshopper definition requires the use of plugins. It seems that all the Toro components create points that feed into a single point container. Could you not internalize this data for us?

Hey Volker,
i just created a new model, so you can work with the file without having the Toro plug in.

Stadion (41.6 KB)

This is easy enough to do with the Relative Items component. However, for that to work, you must first make sure that the order of the points in the two lists run in a circle around the arena.

So that the numbering of the points runs from 0 ascending along the circle? Do you know how to change the numbering or sort the points?

Yes, I am doing it right now.

Here’s one possible method. (40.9 KB)

Used the circle from the beginning of your definition to sort the points. Upper points list had one duplicated point so I culled it.


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Seems you beat me to the punch.

Stadion Bogen (58.6 KB)

I did not know about the Sort Along Curve component, so I went farther back into the script to make sure the points were in order at creation. Thank you for this.

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Thank you so much for your help Volker! I’m sorry that you had to deal with this messy file, I’m still at the very beginning as a user of grasshopper. Thank you!! :smiling_face:

Thanks for your help @kev.r

maybe someone can help me here again. it’s about the same design. the two main arches of the stadium that span over the stadium roof should serve as a connection point for the cables. exactly at this connection point are also connected rhods which in turn connect the two main arches with each other. these connections should only be made above the roof opening of the stadium, i.e. in the middle of the arches which make up about 1/3 of the total arch length. after modeling the stadium like this in grashopper, i transferred these lines to rfem via the rfem interface. however, rfem does not calculate the model for me because the connection points for cables and rods are not on the main arches. if you zoom in closely in rhino (see screenshot), you can also see that the points are slightly next to the arch. i have not yet been able to find out why this is the case and i have not found a solution to create this connection point differently so that its lying on the arch. the divide curve command does not seem to work here in any case. does anyone have any ideas on how i can proceed here? (168.1 KB)

You have to zoom the Rhino window an extreme amount to get the view in your screenshots. If you measure the distance between the curve and points in your file, the maximum deviation is 3.55E-14 (within expected floating point precision).

I don’t have the plug-ins you are using, so I can’t determine where your problem is. This minute distance between the curve and points should not cause a problem.


Yeah I thought the same but I can’t find another reason for rfem not calculating the model. I tried to work with point on curve because when zooming in it shows that the points really are exactly on the curve. However this is way too complicated and I thought there has to be another way. Maybe someone else who also works with the rfem intersection knows how to solve this. Thanks so much anyways @kev.r