UE5 early access something broken in physics? can someone help 5.0EA


I am a beginner and i run into some odd behavior with UE5EA, it is related to physics:

Simple setup empty level with movable floor (roll and pitch controllable with keyboard) with a sphere with physics enable nothing else, in UE4 if i move the floor the ball start moving, in UE5 it is not working. If i drop the ball and it did not stop moving i can control it by moving the floor, but as soon as it stops moving it will not work any more. Does any one have any idea, is it a bug or something has changed in UE5 and have to set it up? you can check on YouTube the behavior UE5 early access physics broken? (can someone help with this?) use CC no audio - YouTube

I did a little progress, the mesh “goes to sleep”. the only option that i found to interrupt the sleep is by using a blueprint( with a static mesh) as actor and i found a function “Wake Rigid Body” that can be “activated” with an “Event Tick” or with and event called “On Component Sleep” but this seems to be a little to complicated for an simple problem.
You can see in the attached YouTube video UE5 sleep actor - YouTube the red ball is the static mesh, the green and blue are the blueprints(identical), the only difference is that the green one has the “anti sleep” and the blue one does not.

Any other possibilities to never go to sleep. Any ideas/options?

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Hello, I have faced this problem, the simulated proxy physics body goes to sleep when its speed reaches zero, for my case the body goes to sleep in the function FPhysicsReplication::ApplyRigidBodyState() exactly in this part

AsyncDesiredState.ObjectState = AsyncDesiredState.Proxy->GetGameThreadAPI().ObjectState();
AsyncDesiredState.bShouldSleep = bShouldSleep;

What is also weird is that when it goes to sleep the Objectstate is set to sleep but the bShouldSleep(Bool) is set to false, so this inconsistency made me think that it was probably a bug.

So if you have managed to set the physics body to never go to sleep please tell me because I don’t want to edit the Engine :smiley: .

A quick solution I have found, You can make a custom physics material and attach it to your physics asset, after that set the angular threshold speed and linear threshold speed to 0 in the physics material and the body won’t go to sleep.

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