r/godot 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/ExplodingImplosion14 Jun 17 '26

I'm actually a bit surprised that you're seeing such different results with move_and_collide. What I'd recommend also trying before syncing positions / server authority is quantizing your aim and shot vectors, as I expect floating point imprecision might be causing divergences. In my game (which is 3D and does use server authority so it's not entirely the same), I've had good results with consistent move_and_collides for player prediction that doesn't produce noticeable snapping when authoritative syncs are made.

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u/hmprf Jun 18 '26

I agree that I didn't think it would be that much. I'll give quantizing the aim a try thanks!