News Unreal Engine 4.23 adds Chaos, improves ray tracing

With Unreal previously using the PhysX engine (remember, GPU PhysX was only a small aspect of the engine itself) and PhysX going open source last year (BSD3, so only the opyright notice needs to be tucked into the source and not mentioned in any marketing materials), I wonder how much of Chaos is a whole new engine and how much is just PhysX with the numbers filed off.

 

Chaos probably still uses an underlying physics library to do all the maths - why bother reinventing that - and chances are that's physx.