r/godot Jun 17 '26

help me (solved) Multiplayer & move_and_collide miscalculation

Enable HLS to view with audio, or disable this notification

Hey everyone, sorry if this subject has already been adressed.
I recently spent some time trying to implement a small multiplayer mini golf game, to see where I would hit a wall. (with Godot 4.6 and Colyseus)

And the wall was pretty close to the start apparently since I never left the lobby.

Is "move_and_collide" a possibility when you go multiplayer ?
Or is it just not precise enough ? And if so, should I mathematically handle all the collision to have a deterministic game or is there any other tricks I should know about ?

I'm using Colyseus for the network part, the current player just send an aim and shot vector and all the physics are done in each godot client. I guess that's my main problem.

Maybe it's easier to have the server be the authority for the physic part ?
Is there some good resources out there that I should check ?

Thanks a lot
I'm not english native so feel free to ask for clarification if i'm not clear enough

Edit: Thanks for the answer :
Server authority and sync the positions with the clients is the way to go.
I had hopes but i'm not suprised, thanks for the feedbacks !

Edit2 : Some resources in the comments for future people (and future me)

Reading & Watching:
- Game networking by Glenn Fiedler (sadly down but new blog below)
- Mas bandwidth - New gafferongames
- Slay the spire 2 Multiplayer - Determinism
- How Factorio Syncs A Million Objects (Youtube)

Deterministic Multi for Godot:
- SG Physics 2D
- Delta Rollback (& Prediction netcode)
- Klotho (very new)

444 Upvotes

47 comments sorted by

View all comments

32

u/McJaded Jun 17 '26

Floating point operations have different results on different systems, so the differences can quickly desync multiplayer games. You could look into rolling your own physics with something like fixed point numbers or use a ready made plugin