Recently, I created a network of connected polylines. I wanted to make them look elastic, so I used a POP Grain on polylines + POP solver, with point attribitues like restlength, targetstiffness etc. It works, but the polylines look very "flabby", like they're made of fluff, not strong rubber. I tried all the things below, nothing changes this flabby look. Any suggestions?

1. POP Grains -> Explicit Constraints -> Stiffness, set it to 100000
2. On points, setpointattrib(0, "targetstiffness", @ptnum, 100000);
3. On points, setpointattrib(0, "constraintstiffness", @ptnum, 100000);
4. On points, shorten the restlength: f@restlength*=0.5;

You'd be better off using vellum hairs or vellum strings.

The main difference between pop grains and vellum is that grains can only maintain length relationships between points, while vellum can also maintain angle relationships. This is controlled via bend stiffness, going from lower to higher values will transition the behavior from string to rubber to wire.