Weird rope sim collision behaviour with two anchor points [UE 5.1]

Hey everyone!
I’m trying to create a gpu rope simulation in UE 5.1. I followed this tutorial to get the basic behaviour down. With only one anchor point there were no collision or physics problems.

Afterwards, I introduced a vector that controls the position of the final particle, the distance between particles is calculated from the distance between origin and final point. The final point ignores physic forces the same way the origin does. Now, I wanted to introduce collision. This is the part that I’m stuck on. If the particle system isn’t moved the built-in collision (distance field-based) works fine. But once the final point moves during runtime it’s all over the place.

I found a post on here that details a system that’s pretty similar and the collision problem was solved with the help of a custom module, however that approach didn’t improve my case, unfortunately.

First part without Collision, at this stage it looks right but of course there is no collision. Second part with built-in collision and third part with custom Collision. Both work with the small rope on the ground (although the custom behaviour doesn’t work as well as the built-in one in that case) but both have issue when the end point is moved.

Does anyone know what could cause this weird behaviour? Or has anyone here successfully implemented collision on a rope sim with two anchor points and could give me pointers how to achieve the right behaviour?

the post with the costum collision module I mentioned is this post (since I’m a new user I wasn’t allowed to add more than two links on one post :sweat_smile:)

As mentioned in my older thread, this is caused by particle being unexpectedly killed by the Collision module Distance Fields type when the particle is “inside” the collider.

Only from UE 5.4 onward, there is a new option to NOT kill the particle, so you don’t need to write your own collision module for that reason anymore.

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