# Diagrid Gridshell Problem

Hi All

I have created a simple diagrid for Gridshell uplifting as attached, the result seems fine but there is just a small problem that I could not figure out which is when the stimulation is finished (pls Grab), there are 2 Gridshells in the result.
As you can see one of them is uplifted correctly the extra one (which shouldn’t be there) is lying distorted (it can be grabbed too).

I suppose its to do with the way I draw the Polylines which is causing this , can anyone point me into the right direction?

Many thanks!
Yutaka

dia grid grid shell problem.gh (17.2 KB)

The reason there are 2 gridshells in the result is because the input polylines do not have any vertices where they cross, so they form 2 separate grids

Here’s an easier way to create this sort of diagonal grid.
As for the staying in plane - for something like this which starts out completely flat and needs to buckle up into a 3 dimensional shape, there needs to be some small out of plane trigger. Here I’ve shown it with a very small vertical force applied upwards to all nodes.
gridshell_help.gh (16.0 KB)

I’m not sure this pattern of supports is very good for an elastic gridshell though. Fixing all the boundary points of a diagonal grid on a square then pushing them in doesn’t leave enough degrees of freedom for the shell to form a smooth shape. Normally you would want to have some parts of the boundary free to slide or open up.

Thank you Daniel well noted the common crossing points issue thanks!

As for your comments regarding the Anchor Points, I have tried to make it open on both sides (pls see attached file), is this what you mean?

I have also tried to make a Hexagonal Grid attached herewith for your comments, I am sure you would have a much better suggestion or solution to this and highly looking forward to hearing from you!

Thank you so much!
Yutaka

diagrid gridshell_daniel.gh (38.4 KB)

hexagonal grid.gh (24.3 KB)