Linking curve end points

It’s difficult to know how to describe what I’d like to do, which is maybe why I haven’t found a simple way. I often select multiple curve points or endpoints at the same time, and move them together, changing the geometry of multiple curves simultaneously, while maintaining their connection point. it’s not possible to group selected endpoints of curves… so is there a way to link them, so that if a curve that shares endpoints with others in a web is moved, the curves attached to it stretch to follow and remain attached?

maybe this is a grasshopper thing.


Join the curves, and the endpoints will merge to a single point, so you can manipulate the two ends together.

right, that works with two curves. but what about three or more?

You cannot join more than two curve endpoints together to form one polycurve - that is the principle of Rhino’s NURBS geometry. So “Y” or “X” structures of three or more joined curves are not allowed.

The question is what to you need to do with this curve geometry…? It is possible to have more than two unjoined curves meeting at a common point, in base Rhino to move then at the same time, you just need to window select the “node” so that all curve endpoints are selected together. It’s of course also possible to construct the curves using Grasshopper, using a fixed point as a reference, moving that point will modify all the curves at once. As per above, they will still not be all joinable once baked into Rhino geometry though.

However, if your node connections are all lines, what you are probably looking for here is using meshes. Any number of mesh edges can meet at a mesh vertex. You can move the vertex point and all the attached edges move with it.

If you have a line network, you can convert it into a mesh using the _MeshFromLines command.

Thank you, I think window-selecting multiple coincident curve endpoints is easy enough, and for more complicated responsive geometries I guess grasshopper would be the best answer. Appreciate the help!