Physics performance problem 70ms/f

When loading a save game in my project where everything else is in order (the number of actors and components re-spawned is the same as other games and actors interact appropriately), but the framerate is absolutely horrible. It gets worse if the same game is saved/loaded repeatedly, but the actors and components remain stable and the level is reloaded between each load so all objects are cleared in between each save/load cycle.


I can destroy all actors and folliage in the game, which will see this broadphase lower BUT if I start moving around with a character, it spikes right back up to 70ms. This test case takes ~10 hours of regular game play with saving and loading in between to get this bad and I don’t know where to even begin to try recreating this in an empty project. Leaving the project for hours without playing DOES NOT cause it to happen.

What happens during postBroadPhase? I haven’t been able to figure this out. Since the number of components saved are the same. I have tried switching to MBP broadphase, and it had no effect on the postBroadPhase.

Any suggestion is appreciated!

This turned out to be an engine bug ( Unreal Engine Issues and Bug Tracker (UE-76873) ). Calling RecreatePhysicsState in key places resolved the issue for me.