DESCRIPTION 
This script builds up on the script “Pop Up Grid: Diagonals” and additionally adds the tie direction. This matters, since ties, depending on their orientation, might get jammed when the grid deforms. They must be placed in an orientation that allows the required grid movement.

PROCEDURE:
The script evaluates each node’s crossing member angles before and after deformation and identifies the tie direction where the angle becomes larger, i.e. no “squeezing” of the ties would take place. This decision is then mapped onto the flattened grid to provide accurate fabrication instructions.