Unity 6 changed physics engine?(Into PhysX) and now it's really buggy?

Unity Engine
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What used to work in Unity 2023, now is getting crazy in Unity 6.
It seems like ragdolls behave really weird.
Specifically, I am trying to have a situation where I use impulse force on a ragdoll to simulate a kick.

However, the ragdoll doesn’t seem to respect angle limitations on bones. In additions, bones seems to stretch out of the joints, and do crazy things.

Is this a bug in the new Unity 6?

Could it be that Unity 6 now force PhysX and that’s how PhysX works?

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What do you mean “force”? It’s always used PhysX for 3D.

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I did notice changes from 2022->2021, where the “automatic center of gravity” didn’t quite behave the same. But I haven’t seen similar changes from 2022->2023/6 in the limited testing I’ve done there.

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Hey!

There are some massive changes internally going into Unity 6 and beyond. Let me confirm it’s still PhysX, like it used to be for years before. However, maybe, something was lost in the refactoring processes, I’ll check with the team. Any chance you have a repro, or a reported bug#? Thanks.

A

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similar issue here,

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Physics is also totally broken for me as well.
With AnticulationBody specifically.

* Convex MeshColliders no longer work
* Also maybe something wrong with “SetDriveForceLimit” or “ArticulationBody.transform” no longer updates transform in FixedUpdate

I upgraded from Unity 2022.3 which was working perfectly.

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Physics are indeed broken in all sorts of ways in Unity 6: joints, rag dolls, articulations, and sometimes even basic rigidbody behavior have ceased to work properly.

Will try and send bug reports for each specific issue.

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Reset physics button is gone in unity 6000.0.5 for the project settings also please get rid of this limitation as it should have been fixed for years now: Couldn’t create a Convex Mesh from source mesh, within the maximum polygons limit (256). The partial hull will be used. Consider simplifying your mesh. Source mesh name:

Also is real time fluid simulations physics can there be a revolutionary system that will allow for 10s of millions for particles that can collide with still super fast frame rates

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Same issue here! Unable to migrate to „production“ ready unity 6
You guys are crazy

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I struggle with the ragdolls too. Or maybe it’s just my terrible coding skills.

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Upgraded the project to Unity 6 and the ragdoll physics and vehicle physics are broken.

This could be due to the Automatic Tensor property or the changes in Rigid body API and therefore all the other physics based joints.

Versions before Unity 6 work perfectly all the way from Unity 2017 to Unity 2023.

Please send bug reports if you can.

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still not working, AddRelativeTorque is broken.

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same the physic is weird

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For me, it feels like the timing of FixedUpdate() being called has changed. I haven’t confirmed how it actually works, but it feels like the execution order of scripts has been rearranged. Physics conflicts with skinned mesh animation.

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It’s your job to keep track of what you change. Don’t make changes without understanding them. Haven’t you tested it? Are you amateurs or what?

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How is it possible that problem was raised 8 months ago, and core unity module like physics is still broken?
I think AddForceAtPosition goes crazy in unity 6 and I would not even expect that such a thing could be broken longer than one or two months.

Can we get any updates? @yant

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I think continuous collision detection is the issue. If you made it none, it would have a lot less issues.

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There is no such thing as none, I guess you meant discrete option, but in my case this is not the cause of the problem, none of my rigidbodies is set to continuous.
BTW my controller makes rigidbody float, so it’s not even about collision, but forces.

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Hey folks! I’m really sorry you’re experiencing these issues, and I’ll bring this thread to the team’s attention. However, I no longer do physics at Unity so won’t be on top of the cases myself.

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I’m not sure if it’s relevant, but please be aware of this bug that is being fixed.
Fixed Timestep setting gets resets to default when upgrading project
As the title suggests, if the fixed timestep is set to anything other than 0.02 seconds, it will be reset to 0.02 seconds when upgrading to Unity 6.

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