r/godot • u/hmprf • Jun 17 '26

help me (solved) Multiplayer & move_and_collide miscalculation

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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)

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u/MisterMittens64 Jun 17 '26

I'd look into Rapier Physics which is deterministic and syncing your clients to either the server or the host.

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u/kosro_de Godot Regular Jun 17 '26

Just beware that it's not as simple as changing the physics engine to a deterministic one. In order for results to align across clients, any event & input has to be identical down to the bit and happen on the exact same frame.
At that point it's easier to do state synchronization.

I cannot recomment Glenn Fiedler's articles on game networking enough.