Creating network connections with Godot is simple — as long as you have the other party’s IP address, and there’s no NAT gateway involved. Unfortunately, that’s exactly the problem in most cases. You don’t know the other party’s IP, and these days, just about everyone is behind a combination wifi router/gateway/firewall with NAT.
Conceptually, NAT hole-punching is pretty simple, and this video explains how it’s done with just netcat.
In a nutshell:
listen on a particular port (e.g. 50001)
nc -u -l 50001
echo ‘hello’ | nc -u ipaddr 50001
echo ‘hole punch’ | nc -u -p 50001 ipaddr 50002
third party exchanges ip addresses
Putting it all together, player A (hosting a game) would require the game to connect to the directory server.
The directory server would list the game as something a player can now connect to.
player B (client who wants to join) will tell the directory service that it wants to connect, and will send its info
The directory server forwards the information to player A (host), player A will then send a packet to player B, and respond to the directory server
The directory server will then tell player B to go ahead and connect to player A.
Player B should be able to punch through to player A
With Godot, the connections from client to host would use ENetMultiplayerPeer.create_client(), which can specify the local port.
I had a setup with nested CanvasLayer nodes. Toggling the visibility of the root CanvasLayer doesn’t hide any nested CanvasLayer nodes. My solution was to listen to the visibility_changed signal, find any CanvasLayer child nodes, and apply the same visibility to them.
This release finally uses Godot Engine 4.4. It adds the GGCraftingSystem singleton and updates the GGInteractable2DStrategyCrafting class to use it. The crafting editor nodes now have prefixes, which makes it much easier to search for specific recipe or item nodes in larger crafting libraries. Some syntactic sugar was added as well. You can now easily …
Once I found out about the Steam Deck’s Desktop Mode, it got even more interesting. Steam Deck’s Gaming Mode vs Desktop Mode You see, the Steam Deck defaults to an analog of Big Picture mode on PC. It runs full screen in “Steam Deck gaming console” mode. But underneath all that is a Linux system …
Arguably, more fun than writing code is removing code. I was assembling a split-screen multiplayer UI. The goal behavior is to show/hide the appropriate displays for the players, depending on how many players there are. Initially, the code to update the UI was very simple, because I started with two players. In that case, you …
Creating a UDP peer-to-peer connection
Creating network connections with Godot is simple — as long as you have the other party’s IP address, and there’s no NAT gateway involved. Unfortunately, that’s exactly the problem in most cases. You don’t know the other party’s IP, and these days, just about everyone is behind a combination wifi router/gateway/firewall with NAT.
Conceptually, NAT hole-punching is pretty simple, and this video explains how it’s done with just netcat.
In a nutshell:
Putting it all together, player A (hosting a game) would require the game to connect to the directory server.
With Godot, the connections from client to host would use ENetMultiplayerPeer.create_client(), which can specify the local port.
Here’s an older example of a signaling server: https://github.com/Faless/gd-webrtc-signalling/tree/master
Related Posts
Toggling Visibility of Nested CanvasLayers
I had a setup with nested CanvasLayer nodes. Toggling the visibility of the root CanvasLayer doesn’t hide any nested CanvasLayer nodes. My solution was to listen to the visibility_changed signal, find any CanvasLayer child nodes, and apply the same visibility to them.
Inventory System 2 Alpha 4 available
This release finally uses Godot Engine 4.4. It adds the GGCraftingSystem singleton and updates the GGInteractable2DStrategyCrafting class to use it. The crafting editor nodes now have prefixes, which makes it much easier to search for specific recipe or item nodes in larger crafting libraries. Some syntactic sugar was added as well. You can now easily …
Godot Engine on the Steam Deck – Developing games on the go?
Once I found out about the Steam Deck’s Desktop Mode, it got even more interesting. Steam Deck’s Gaming Mode vs Desktop Mode You see, the Steam Deck defaults to an analog of Big Picture mode on PC. It runs full screen in “Steam Deck gaming console” mode. But underneath all that is a Linux system …
A GDScript refactoring exercise
Arguably, more fun than writing code is removing code. I was assembling a split-screen multiplayer UI. The goal behavior is to show/hide the appropriate displays for the players, depending on how many players there are. Initially, the code to update the UI was very simple, because I started with two players. In that case, you …