In Unreal 4.26.preview4 the physics constraints setting has no effect, while it is expected to behave like in 4.25.
Perhaps it is related to the announced usage of “Chaos” engine instead of PhysX.
Example project here: GitHub - adynathos/UnrealConstraintsBug: Reproduce a bug: physics constraints do not work in Unreal 4.26
The test scene contains 4 rigid-bodies falling onto a sloped plane.
They have the following constraint settings, from left to right:
- Lock X position
- PhysicsConstraintActor attached to this body, locking X movement and all rotations
The settings have been applied per-instance in the map.
The general intent of the constraints is to keep the body at X=0 and prevent it from sliding down the plane.
Result in 4.25
We run this map in 4.25.3 and observe the constraints preventing the bodies from sliding down the plane.
Result in 4.26
The same map run in 4.26.preview4 shows all bodies sliding the same way. The constraints have no effect.
( I have submitted the report as well )