Probably a dumb question but I’m new here so, what is the default physics engine for UE 4.27.2, I thought it was PhysX, but I noticed the Chaos plugins were enabled as well as PhysX. I know<4.27 use the PhysX, but this caught me off guard.
Hi there,
Welcome to the forums.
The engine versions from 4.23 and 4.27 from the source are available with the experimental Chaos plugin back in the day.
For more details, there is a precompiled demo version on Fab, which also requires the source version:
Chaos Destruction Demo | Fab
Thanks for this info. I was wondering this myself, since 4.27.2 has far superior handling of physics assets simulated using Rigid Body Animation Nodes. The simulation is perfect at any framerate (tested from 30 fps to 240 fps), however in Unreal 5.3.2 and 5.5.4, anything above 60 fps becomes increasingly stiff and essentially breaks the desired floppy bone chain effect. What I don’t understand is why are all the Chaos plugins enabled by default in 4.27.2 (launcher version), if the Engine is actually still using PhysX?
No problem.
That’s a good question. My understanding is that both 4.26 and 4.27 were more like a transition to UE5, having many features still in experimental stage, but since you mentioned better physics in 4.27, I wonder if this was the result of PhysX or Chaos plugins?
According to WildOxStudios, 4.27.2 would have been using PhysX despite having the Chaos plugins enabled, unless I had installed the “4.27-Chaos” build in the Launcher (which I did not). So I guess PhysX really is the reason UE4 has accurate framerate-independent physics. I hope this will eventually improve in UE5 (I have not tested 5.6.0 yet).