Bug: character getting stuck in the floor, then catapulted out of the map

[julkiewicz]

Hi,

I've attempted to integrate UFPS with the following environment asset:

Street New York | 3D Urban | Unity Asset Store

Elevate your workflow with the Street New York asset from Art Equilibrium. Find this & other Urban options on the Unity Asset Store.

assetstore.unity.com

This particular asset has the floor (streets) modelled as a bunch of mesh colliders. The shape seems pretty simple and straightforward.

On the example scene, after UFPS is integrated, I experience a bug where character randomly gets stuck in floor. First it cannot move, then after a while it gets catapulted out of the map. This seems to happen pretty randomly but quite frequently - maybe ~40 sec to 2 min.

Could I get some official support in getting this resolved. Hopefully this sounds like something familiar.

 

[julkiewicz]

Actually, now that I looked into it closer the movement on that scene is completely broken in general. The character gets bounced around in a jerky way. I tried to find any difference between this example scene and the demo scene, but physics materials match, everything else that I would expect to have an impact also matches.

 

[julkiewicz]

Okay, so for those interested, seems like UFPS doesn't work very well with floor meshes that have relatively small faces sticking out. In this particular case there was a pavement curb that was sticking out by about 5cm (in scale relative to a normal realistic character model). And that sticking out curb was consistently getting stuck inside the leg collider.

From what I can gather, generally putting colliders on animated elements is a really bad idea and will lead to unpredictable behavior like this one. Unity physics system was not designed to have colliding parts be moved in an animated way and be "pushed into" other colliders via animation. It can work by accident sometimes, but is very risky. Idk, I don't have a full enough understanding of this package to make a judgement on whether this is fundamentally broken or not.

Either way, since this is just a small demo that I'm building and not some production grade game, I just removed the curbs from the collider topology and now it seems to work more reliably. At least I wasn't able to reproduce this bug again.

 

[Justin]

I'm glad that you are making progress. Generally this occurs when the normal on the collider is in the wrong direction. This will cause the collision detection to miss the ground and not know what to do.