Chaos Physics & Determinism?

As been quite heavily discussed on here for years, there’s traditionally been problems with PhysX and determinism, especially for problems such as solid client side prediction for vehicles in multiplayer games, as well as implementing GGPO-style net code in to UE4, etc.

Now that Chaos has replaced PhysX, there doesn’t seem to be any mentions of the difference. Has anyone figured out if the same problems with PhysX still exist in Chaos?

Discussing it with the author of the FGear vehicle package on these forums, he does not seem to have any answer for this either. But the information would be very helpful if it (hopefully) resolved the problems!

Chaos will interop with a new Network Prediction system, and it has a rewind API to support features like rollback. There are no plans for a deterministic physics engine AFAIK, but Chaos does at least support fixed-tick rates now (and this is currently required to interop).

You can find more information here, and/or you can look at the network prediction plugin on Github in Master branch.