'RigidPointSet' either snaps or anchors points

Hello everyone,

I’m working on a tensile structure that looks like the first photo attached here.

I decided to create a joint for the cables connecting to the poles and so I had to distance them from the center. The first screenshot is before and the second is after…

cables not offset
cables offset

Now that the cable starting points aren’t all the same point, I had to use ‘RigidPointSet’ to keep them on the same plane. Keep in mind, I have different strength for different goal objects. I keep the Anchors and ‘LengthLine’ for rigid lines the strongest, then come the cables and mesh edges. Now that I am using the ‘RigidPointSet’, they tend to either lose the points from being on the same plane or stay in the same starting plane.

I am wondering if there is another way to do it. Thank you in advance.

Tensile Structure.3dm (141.7 KB)
Tensile Structure.gh (149.0 KB)

Your definition is quite complicated. The data dams are a bit of a pain to be honest. To be able to quickly switch off the Kangaroo Solver and reduce navigating / moving back and forth on the GH canvas, you can publish the button and toggle for the Kangaroo solver to the Grasshopper remote control panel. It saves a ton of mouse action.

First thing, I’m not using Pufferfish and Wombat so I do not see all components.

The curve direction of one of your triangles had to be flipped. I internalised all inputs so if someone else wants to continue from here on, they only need the Grasshopper file.

The stitch cables are somewhat messed up. Instead of renaming or shifting the branches, you can use the Relative Items component. The order of the points is based on the curve direction hence you’ll have to flip one of the two curves to get the correct pairs. It could also be done with point groups but if you understand the Relative Items component I think it is the cleaner way.

As a general not, I think on this object I would use different tension for the perimeter and the internal edges of the membranes…

If you look at the Anchor component, there’s a Point and Target input. I’m not going to change your whole definition but what you’re doing with the poles and LengthLine goals could be replaced with an Anchor component.

You can use a CoCircular goal for the 12 points of each of the openings. If you want any control over the diameter of the openings, add a line goal from each point to the average.

I’m not quite sure what your problem was with the Rigid Point Set?

Tensile Structure.gh (149.3 KB)

Thank you for your response. I think I should have been clearer with the issue at hand.

My very first patch (not uploaded) looked like this. The poles were anchored on ground as a pin connection allowing them to lean with the mesh.

When I decided to separate the cable ends as such and use Rigid Point Set to keep them on the same relative plane, I started having some issues.

The issue was that using the rigid point set at high strength anchored the points input in place but at lower strength, the cables snapped. There didn’t seem to be a strength input that would make it. This screenshot shows the points anchored in place.

The screenshot below shows how I resolved this issue.