For that, maybe put some logic to determine if the thing is still in play inside OnComponentSleep, wake all if yes. Should be better than disabling sleep globally (if it works).
Setting âp.Chaos.Solver.SleepEnabled 0â seems like a great performance sync and so does increasing the number of iterations. Thanks for proposing them though but any further opinions are welcome.
Wouldnât setting p.Chaos.Solver.SleepEnabled 0 invaliate any kind of optimizations for physics actors? Effectively leaving all of them to tick physics even if they are say, just sitting on a shelf, not being touched by anything. This seems like a very bad idea if you have any meaningful number of physics objects in your scene.
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The (hopefuly temporary) solution we came up with was creating a Timer by Event with a WakeRigidBody every .1 seconds during the use of the constraint, which gets invalidated once done. This way we donât have to disable chaos sleep entirely which again, sounds like a terrible idea long-term.
Again, this needs a proper address from the unreal devs since its very much broken the way it behaves now.
.1 seconds is not that much different from tick performance-wise, and youâd mess up all velocity and impulse calculations. OnComponentSleep will work if you can get it to fire, otherwise might as well just use c++ tick.
Also from my testing at 128 iterations Chaos still has slightly better performance than UE4 Physx. I think that oneâs intended.
Trying to make hair simulation with phys bones (I did a lot of it in ue4) but in ue5 its not working at all⌠constraints are unpredictable
Is this still a thing as Iâm migrating a VR project that uses Physics constraints on the hands to UE5 & Its a mess. the once tight constraints are now swinging all over the place not anywhere near my hands and Nothing I do has any effect.
I also noticed that even with constrained objects named in the details panel It donât seem to work and my physical bits sit on the floor . So I forced one of them in the graph by using the set constrained components node But then both were working but, but swinging all over again?
Im confused
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That actually helped me deal with my problem. Thanks.
Yes for what I needed this helpsâŚrather than every tick I just added the âsimulate physicsâ at the beginning of the event that I needed (itâs casting a line on a fishing rod) but thank you a bunch!
Hey everyone!
Are folks still having issues with the Chaos iterations and physics constraints?
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Yes, still an issue, both with it freezing mid-air at certain times and 2 objects connected by a constraint resulting in a far larger(longer) constraint distance during play.
Hi, yes, I found unstable behavior of vehicles in the City Sample, City_Small_LVL, where a few cars are colliding to each other, and warning messages appear in the output log:
âLogChaos: Warning: Collision handler encountered invalid actors and could not recover componentsâ (UE5.1 editor build).
Any advice is appreciated.
Thanks.
Itâs much better for me now, only 2X the default iterations is needed for accurate simulations (instead of like 20X), and the freezing is fixed.
Hello, yes this still seems to be a problem. Iâm working in Unreal 5.0 and trying to make physics hands in VR by using physics constraints. Just like everyone else here, the hands lag behind massively no matter what I do. If the hands are motionless for too long, then theyâll freeze in place as well.
All of this works perfectly in UE4 so it seems that UE5 caused this issue. Have there been any updates as to whether this is being fixed? This seems like a huge issue as physics constraints just donât work anymore for a lot of their intended applications.
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Yes still an issue. I made a vehicle trailer system (with hitch and un-hitch) in UE4 and it worked fine. In UE5 the trailer just started flipping out as soon as you start to move causing your vehicle to fly around the map. This is really holding up production of the game. It seems the only way it can work (somewhat) is if you constrain the trailer in the editor viewport before pressing play, but that means you canât hitch and un-hitch trailers in-game, which is no use.
We will follow up with the dev team on this to see if they can shed some light on the issues that are presenting!
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Hello, have you found the fix for âLogChaos: Warning: Collision handler encountered invalid actors and could not recover componentsâ
Sometimes my AI gets stuck in floor/walls because of this invalid actor thing, otherwise it just moves ai from floor/wall to normal place automatically but when this warning happen they keep stuck
Iâm relaying some information from colleagues here:
In UE 5.0 early access physics constraints were solved with a non-linear method that was more accurate but also more costly in terms of performance. When we left early access, we switched to a linear solver but the non-linear solver is still available and opt-in via a cvar:
p.Chaos.Solver.Joint.UseLinearSolver 0
If you noticed a big change in behavior between 5.0-EA and 5.0, switching back to the non-linear solver via the above cvar may be worth trying.
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Thankyou, it does fix my problem, now my door with physic constraint can rotate properly now, thankyou very much
I had to convert from 4.27Plus and was really dreading it because the game is heavy physics based and I had tested Chaos in 5.0 and it was slow and buggy. Now in 5.4 I had to upgrade and it went so much smoother than I thought. I did spend about 2 weeks fine tuning all the constraints but am happy with Chaos and proud of the engineers at Epic. Here is a video of a 100% physics motorcycle and rider running at solid 60 FPS on PS4 and physics running at 120FPS: https://youtube.com/shorts/mrFF2TDatv4?si=lIbVMr2C9yclBMxN