Yes! This is exciting to see. Erin Catto is such a cool hacker. Thank you, Erin, for sharing your code with the open source community.
There wasn't anything about determinism in the announcement, but I'd really love to see some more about that, too. Trying to use Unity's built-in physics to make a networked billiards game is quite troubling, when none of the clients can happily agree on what happened.
I was looking for the same thing. There is a replay mechanism, so it seems to be deterministic. But with floating point physics, not across platforms. Though -ffast-math is unsupported according to the documentation, so maybe it is intended to be deterministic across platforms? https://box2d.org/documentation3d/recording.html
EDIT: Clarified meaning about ffast-math
Ah, found more: https://box2d.org/documentation3d/md_simulation.html#autotoc... "Box3D is designed to be deterministic across thread counts and platforms."
This is absolutely fantastic!