I am a student and have recently started exploring the kangaroo library commands inside python. We could have differential growth curve using python scripting. But when we tried to do the same thing for mesh grid, we started getting invalid lines. Just not able to figure it out why we keep getting this.
That example script is working on a closed polyline - growing and dividing it with collision pushing the points apart.
For the collisions it uses the start point of every line (which for a closed loop means one point per segment). If you do this for a whole grid of lines, you are duplicating many of the points where they connect, so trying to do collision between a point and itself, leading to the error.
You’d need to create a duplicate free list of points to feed into the collider goal.
Also - the curve in the example is on a plane, but you are using lines in space. When these push apart they will not stay on the mesh unless you add another goal to keep them there.