Help Obi Rope Cursor ChangeLength With Collision

[zack_Lee]

When I was using Obi Rope, I wanted to dynamically modify the length of the rope. But modifying the length will cause the collision between the rope and the rope to fail, and the two ropes that are entwined with each other will untie, is there any solution?

[josemendez]

When I was using Obi Rope, I wanted to dynamically modify the length of the rope. But modifying the length will cause the collision between the rope and the rope to fail, and the two ropes that are entwined with each other will untie, is there any solution?

Hi!

This should not be the case, collisions and length are completely unrelated to each other. Could you be more specific? How/when are you changing the length of the rope? does the area of the rope that your cursor is using as source (its sourceMu parameter) have collision filters that might filter out collisions?

kind regards,

[zack_Lee]

Hi!

This should not be the case, collisions and length are completely unrelated to each other. Could you be more specific? How/when are you changing the length of the rope? does the area of the rope that your cursor is using as source (its sourceMu parameter) have collision filters that might filter out collisions?

kind regards,

I am currently facing an issue where my two ropes get entangled with each other. I have enabled surface-based collision for the ropes. However, when I modify the length of the ropes, they sometimes pass through each other, possibly due to excessive forces. I have attached the control points of the ropes to an object, and when I move the object, it changes the length of the ropes.    

---

If it is not related to changeLength, how can I prevent the ropes from passing through each other under fast movement or strong forces?

[josemendez]

[..], possibly due to excessive forces. [...]

If it is not related to changeLength, how can I prevent the ropes from passing through each other under fast movement or strong forces?

Hi!

Make sure the "forces" you're referring to are actual forces, instead of just setting the position of a specific particle on the rope (via eg. setting the position of a static attachment). This is akin to teleporting part of the rope and collisions will be inevitably missed.

You can use more substeps and/or collision iterations to increase collision robustness. The manual has an in-depth explanation of how the engine works internally and how substeps and iterations affect simulation quality: http://obi.virtualmethodstudio.com/manua...gence.html

You may also increase the solver's collision margin parameter to track contacts before ropes actually collide with each other.

kind regards,