#chaos Physics Constraint Component functionally different from PhysX constraint

Hello my project made use of the Physics Constraint Component in 4.26, which used the PhysX library. In the current available UE5.0 Preview 2 build, the PhysicsConstraintComponent no longer performs the same and it breaks the things we were using it for. The current functionality difference can be easily demonstrated by opening an empty project in both 4.26 and 5.0 prev2 and creating an identical setup.

I used a sphere and cone, Set the cone to simulate physics, add the PhysicsConstraintComponent on the cone, and configured these settings as pictured here:

You should be able to run the PIE in simulate mode and move the cone around to see it swing. in 4.26 it swings in a nice circular arc, but in 5.0 it moves in a box-like limit and looks very unnatural. Presumably this change is due to replacing the PhysX constraint with the new Chaos physics engine constraint solution in 5.0.

Hi, im back just to follow up on this issue and confirm if the issue is being tracked. Should I make a ticket in the issue tracker? Also, need to know if Epic Devs are planning to not fix it, in which case I would need to budget time to develop a custom solution in my own project for the feature I was using constraints for.

I would love to transition to UE5 and start using the new tools like Metasounds and nanite.

This issue still exists in the 5.0.0 release version, available yesterday, April 5 2022.

I can relate, it moves in a box-like limit and totally breaks the UE4 behavior, I really would like to have some help on that :disappointed_relieved:

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Yup, looks really similar to what I see. Thanks for the video. Hope they can fix this soon. It breaks some important parts of our game.

Yep, I just hope it is not working “as expected” then it would never be fixed

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Same problem for us, even a simple constraint is bugged and unusable. We should know if these are going to be fixed and work like with UE4.X or if they will be removed because, at the moment, there’s no way to use them in UE5.


They’ve got my issue report and fixed it for 5.1 :partying_face:


Woohoo! Fantastic news. Thanks for letting us know, GTNardy.

I still seem to be getting very broken physics constraints similar to what can be seen in the video -with an arbitrary length just coming into existence- on the latest 5.1

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