DOTS netcode floating origin support

[astral dock]

This is a bit of a niche thing, but does/will DOTS netcode support floating origins for large worlds?

[gritty glade]

It's not built in as far as I'm aware

floating origin in multiplayer is an... interesting topic

like, how do you handle that on the server?

[astral dock]

it definitely is, but it is possible because of games like DCS

[gritty glade]

sure it's just not using doubles?

a quick google seems to imply this, but i can't actually see a dev source to confirm

[astral dock]

there was a 32 version at some point, but it looks like they dropped it after floating point limitations

pretty sure unity doesn't support doubles either for transforms

looks like you were right

but games like VTOL VR do exist as a multiplayer game with vast distances, and after decompiling it, it looks like the developer also uses floating origin

so it does seem possible

[gritty glade]

the question is, what is the origin on the server though

if 1 player is -100,000 and another player is 100,000

how do you resolve it

not saying it's impossible, it's just complicated

[astral dock]

based on what I can see, the game uses a lot of client side physics for players, and they might keep track of their unedited origin position to be sent to the server

[gritty glade]

i have seen games use floating origin only on clients

[astral dock]

but there's also server side ai's, which I'm curious on how they work

[astral dock]

the server was built in unity

from what I can tell, the server's physics are accurate enough that server side AI's/objects don't have to worry too much about major miscalculations, it's just visual glitches are the main worry due to minor millimeter glitches causing major visual bugs on clients

[gray dome]

This is a topic of current active research for future entities & netcode & unity versions but no decisions have been made about it yet

[astral dock]

it would be great, but I don't think server authorative (with client prediction) physics movement would work at exceptionally great distances due to eventual floating point precision errors you would get on the server, but good luck nonetheless!

[carmine kraken]

how much is "exceptionally great distances"?

[carmine kraken]

I have "floating origin" on my netcode (but it uses 2 bytes floats to send position) writing first the player position as a full float on the first 12 bytes of buffer and then writing all positions of all entities (i`m using snapshot interpolation) relative to it

writing "origin" as double can work here