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+--- Thread: Help Obi Particles stuck below ground collider (/thread-4438.html)
Obi Particles stuck below ground collider - aderae - 16-01-2025
Hello,
I sometimes see some Obi Rope particles sometimes get stuck below the ground collider making this visible bug. I tried to play with collision settings but couldn't get my head around. How can I prevent this behaviour? I have attached 2 pictures one with mesh and one with particle rendering
Thanks!
RE: Obi Particles stuck below ground collider - josemendez - 16-01-2025
Hi,
Which kind of collider are you using for the ground? Volumeless colliders or very thin colliders can have this problem, called tunneling. Happens in all existing physics engines, a long time ago I recorded a video on this subject:
Assuming you're already using continuous collision detection (setting in ObiSolver) and it's not enough to prevent this issue, the simplest fix for this is to just make your collider thicker. The second simplest solution is to reduce Unity's fixed timestep, but note this will impact performance.
kind regards,
RE: Obi Particles stuck below ground collider - aderae - 17-01-2025
Thank you. Since this is a mesh collider that is procedurally generated, there is not a very optimized way to make it thicker. However after your reply and fiddling more with it, I realized it is caused by the players collider actually pushing the rope into the world. I disabled it and this is fixed for now.
RE: Obi Particles stuck below ground collider - josemendez - 17-01-2025
(17-01-2025, 09:54 AM)aderae Wrote: However after your reply and fiddling more with it, I realized it is caused by the players collider actually pushing the rope into the world. I disabled it and this is fixed for now.
Glad you found the cause!
Note that no matter how accurate continuous collision detection is, it can't do anything to help if another object pushes the rope trough a collider. It can only improve robustness for fast moving objects and/or thin colliders.
kind regards,