Help on configuring Obi Rope to simulate sewing.

[niZmo]

Hello,

Just want to start by saying I really like Obi Rope, it performs excellently and I can see a lot of potential in the platform.

Now for my issue: I am trying to simulate sewing, like thread and needle sewing. I am just having some difficulty with configuring the rope to look and feel like thread (or dental floss). To clarify, currently my Obi Rope is stretchy, bouncy, and too fluid. When I move the needle (with thread pinned to it), I need the thread to have 0 stretch, 0 bounce, and stiff enough that simple movement like up-down or left-right does not make the thread jiggle like a wet noodle. And of course, it should have enough bending that will allow for tying relatively tight knots, but that is less of a priority than the thread movement itself.

What are some options to play around with? Or at least which options should I avoid or disable completely to get rid of stretch, bounce, and spring, and add stiffness?

Thank you very much!

You’ll always have some kind of stretching. Tying knots where it won’t undo will take a lot of resources, I don’t even know if it’s possible. You have to go to your solver and crank up the iterations for you distance constraint to 20-30. Same on the collision iteration. For your rope turn the resolution all the way up and turn on self collisions. To not stretch the rope you’ll have to write a custom script. You can get the total length of the rope once interacting with it, and once it’s length increases then stop the needle from being move further from the attached particle. If your rope does have a attached particle somewhere (not the needle) you can also use tether constraints to prevent the rope from stretching naturally.

To make the rope a little stiffer you need to mess with the bending constraint. The rope should have the bending constraint on it where you can set the bending amount and in the solver you can increase the accuracy of it by turning up the iterations.

You can read up on it here.