Actual multiplayer woo!

Game.cs

@@ -0,0 +1,9 @@
+public partial class Game : Node
+{
+	[Export] public Player LocalPlayer { get; set; }
+
+	public MultiplayerManager MultiplayerManager { get; private set; }
+
+	public override void _EnterTree()
+		=> MultiplayerManager = GetNode<MultiplayerManager>("MultiplayerManager");
+}

game.tscn

@@ -1,20 +1,34 @@
-[gd_scene load_steps=8 format=3 uid="uid://puuk72ficqhu"]
+[gd_scene load_steps=11 format=3 uid="uid://puuk72ficqhu"]
 
-[ext_resource type="PackedScene" uid="uid://bwfuet1irfi17" path="res://scenes/workshop.tscn" id="1_m8m3w"]
+[ext_resource type="Script" path="res://scripts/MultiplayerManager.cs" id="1_7shyh"]
-[ext_resource type="Shader" path="res://assets/shaders/outline.gdshader" id="2_yvnqw"]
+[ext_resource type="Script" path="res://Game.cs" id="1_uywdd"]
-[ext_resource type="Script" path="res://scripts/OutlineCamera.cs" id="3_wd8hf"]
+[ext_resource type="PackedScene" uid="uid://dmd7w2r8s0x6y" path="res://player/player.tscn" id="2_iv2f7"]
-[ext_resource type="Texture2D" uid="uid://lxxfestfg2dt" path="res://assets/crosshair.png" id="4_06ang"]
+[ext_resource type="PackedScene" uid="uid://bwfuet1irfi17" path="res://scenes/workshop.tscn" id="3_4u5ql"]
-[ext_resource type="PackedScene" uid="uid://c5ooi36ibspfo" path="res://ui/menu.tscn" id="4_77nbu"]
+[ext_resource type="Shader" path="res://assets/shaders/outline.gdshader" id="4_gacvj"]
-[ext_resource type="Script" path="res://scripts/Crosshair.cs" id="5_i8gkf"]
+[ext_resource type="Script" path="res://scripts/OutlineCamera.cs" id="5_qpc14"]
+[ext_resource type="PackedScene" uid="uid://c5ooi36ibspfo" path="res://ui/menu.tscn" id="6_ol0j5"]
+[ext_resource type="Texture2D" uid="uid://lxxfestfg2dt" path="res://assets/crosshair.png" id="7_0l5tv"]
+[ext_resource type="Script" path="res://scripts/Crosshair.cs" id="8_mfhgr"]
 
 [sub_resource type="ShaderMaterial" id="ShaderMaterial_ke1l3"]
-shader = ExtResource("2_yvnqw")
+shader = ExtResource("4_gacvj")
 shader_parameter/line_color = Color(1, 1, 1, 0.75)
 shader_parameter/line_thickness = 2.0
 
 [node name="Game" type="Node"]
+script = ExtResource("1_uywdd")
 
-[node name="Workshop" parent="." instance=ExtResource("1_m8m3w")]
+[node name="MultiplayerManager" type="Node" parent="." node_paths=PackedStringArray("LocalPlayer", "Players")]
+script = ExtResource("1_7shyh")
+LocalPlayer = NodePath("../Players/Local")
+Players = NodePath("../Players")
+PlayerScene = ExtResource("2_iv2f7")
+
+[node name="Workshop" parent="." instance=ExtResource("3_4u5ql")]
+
+[node name="Players" type="Node3D" parent="."]
+
+[node name="Local" parent="Players" instance=ExtResource("2_iv2f7")]
 
 [node name="OutlineViewportContainer" type="SubViewportContainer" parent="."]
 material = SubResource("ShaderMaterial_ke1l3")
@@ -34,7 +48,7 @@ render_target_update_mode = 4
 [node name="OutlineCamera" type="Camera3D" parent="OutlineViewportContainer/OutlineViewport"]
 cull_mask = 2
 current = true
-script = ExtResource("3_wd8hf")
+script = ExtResource("5_qpc14")
 
 [node name="HUD" type="Control" parent="."]
 layout_mode = 3
@@ -45,7 +59,7 @@ grow_horizontal = 2
 grow_vertical = 2
 mouse_filter = 2
 
-[node name="Menu" parent="HUD" instance=ExtResource("4_77nbu")]
+[node name="Menu" parent="HUD" instance=ExtResource("6_ol0j5")]
 visible = false
 layout_mode = 1
 anchors_preset = 15
@@ -69,5 +83,5 @@ offset_right = 20.0
 offset_bottom = 20.0
 grow_horizontal = 2
 grow_vertical = 2
-texture = ExtResource("4_06ang")
+texture = ExtResource("7_0l5tv")
-script = ExtResource("5_i8gkf")
+script = ExtResource("8_mfhgr")

player/AnimationController.cs

@@ -22,11 +22,8 @@ public partial class AnimationController : Node3D
 		_walkBackwardAnim = _animTree.GetAnimation("walk_backward");
 
 		_rootBone = GetNode<BoneAttachment3D>("Root");
-		foreach (var child in FindChildren("*", "BoneAttachment3D")) {
+		foreach (var bone in FindChildren("*").OfType<BoneAttachment3D>())
-			var bone = (BoneAttachment3D)child;
+			{ bone.OverridePose = true; _bones[bone.Name] = bone; }
-			bone.OverridePose = true;
-			_bones[bone.Name] = bone;
-		}
 
 		// We disable the AnimationTree while in the editor so our
 		// BoneAttackment3D nodes don't get updated, resulting in

player/CameraController.cs

@@ -7,8 +7,8 @@ public partial class CameraController : Node
 
 	public Transform3D DefaultTransform { get; private set; }
 
-	public float CurrentPitch { get; set; }
+	[Export] public float CurrentPitch { get; set; }
-	public float CurrentYaw { get; set; }
+	[Export] public float CurrentYaw { get; set; }
 
 	public static bool IsMouseCaptured
 		=> Input.MouseMode == Input.MouseModeEnum.Captured;

player/MovementController.cs

@@ -16,7 +16,7 @@ public partial class MovementController : Node
 
 	public bool IsSprinting { get; private set; }
 	/// <summary> The raw input movement vector with a maximum length of 1. </summary>
-	public Vector2 InputVector { get; private set; }
+	[Export] public Vector2 InputVector { get; private set; }
 
 	public bool IsMoving => LocalMoveVector.Length() > 0.01f;
 	/// <summary> The actual amount the player is moving, relative to the world. Y is always 0. </summary>

player/Player.cs

@@ -1,6 +1,7 @@
 public partial class Player : CharacterBody3D
 {
-	[Export] public bool IsLocal { get; set; } = true;
+	public bool IsLocal { get; set; } = true;
+	public int PeerId { get; set; }
 
 	public MovementController  Movement  { get; private set; }
 	public CameraController    Camera    { get; private set; }

player/Synchronizer.cs

@@ -0,0 +1,12 @@
+public partial class Synchronizer : MultiplayerSynchronizer
+{
+	// Required because `Velocity` can't be synchronized automatically.
+	[Export] public Vector3 PlayerVelocity {
+		get => _player.Velocity;
+		set => _player.Velocity = value;
+	}
+
+	Player _player;
+	public override void _Ready()
+		=> _player = GetParent<Player>();
+}

player/player.tscn

@@ -1,4 +1,4 @@
-[gd_scene load_steps=24 format=3 uid="uid://dmd7w2r8s0x6y"]
+[gd_scene load_steps=26 format=3 uid="uid://dmd7w2r8s0x6y"]
 
 [ext_resource type="PackedScene" uid="uid://bfh3eqgywr0ul" path="res://assets/models/character.blend" id="1_3qh37"]
 [ext_resource type="Script" path="res://player/Player.cs" id="1_a0mas"]
@@ -7,15 +7,36 @@
 [ext_resource type="Script" path="res://player/PickupController.cs" id="2_ns2pe"]
 [ext_resource type="Script" path="res://player/CameraController.cs" id="2_r3gna"]
 [ext_resource type="Script" path="res://player/AnimationController.cs" id="3_5rlwc"]
+[ext_resource type="Script" path="res://player/Synchronizer.cs" id="4_h8li4"]
 
 [sub_resource type="CapsuleShape3D" id="CapsuleShape3D_h1mfd"]
 radius = 0.24
 height = 1.5
 
 [sub_resource type="CapsuleShape3D" id="CapsuleShape3D_l8s0f"]
-radius = 0.28
+radius = 0.24
 height = 1.5
 
+[sub_resource type="SceneReplicationConfig" id="SceneReplicationConfig_dpppx"]
+properties/0/path = NodePath(".:position")
+properties/0/spawn = true
+properties/0/replication_mode = 1
+properties/1/path = NodePath(".:rotation")
+properties/1/spawn = true
+properties/1/replication_mode = 1
+properties/2/path = NodePath("MultiplayerSynchronizer:PlayerVelocity")
+properties/2/spawn = true
+properties/2/replication_mode = 1
+properties/3/path = NodePath("MovementController:InputVector")
+properties/3/spawn = true
+properties/3/replication_mode = 1
+properties/4/path = NodePath("CameraController:CurrentPitch")
+properties/4/spawn = true
+properties/4/replication_mode = 1
+properties/5/path = NodePath("CameraController:CurrentYaw")
+properties/5/spawn = true
+properties/5/replication_mode = 1
+
 [sub_resource type="Animation" id="Animation_5wsog"]
 resource_name = "idle_loop"
 length = 2.5
@@ -784,7 +805,6 @@ input_1/auto_advance = false
 input_1/reset = true
 
 [sub_resource type="AnimationNodeBlendTree" id="AnimationNodeBlendTree_cstk8"]
-graph_offset = Vector2(30, 1.30002)
 nodes/Animation/node = SubResource("AnimationNodeAnimation_ra5r1")
 nodes/Animation/position = Vector2(600, 60)
 nodes/not_moving/node = SubResource("AnimationNodeAnimation_cun17")
@@ -822,6 +842,10 @@ shape = SubResource("CapsuleShape3D_l8s0f")
 [node name="Model" parent="." instance=ExtResource("1_3qh37")]
 transform = Transform3D(-1, 0, -8.74228e-08, 0, 1, 0, 8.74228e-08, 0, -1, 0, -0.75, 0)
 
+[node name="MultiplayerSynchronizer" type="MultiplayerSynchronizer" parent="."]
+replication_config = SubResource("SceneReplicationConfig_dpppx")
+script = ExtResource("4_h8li4")
+
 [node name="MovementController" type="Node" parent="."]
 script = ExtResource("2_1pst4")
 
@@ -864,14 +888,14 @@ use_external_skeleton = true
 external_skeleton = NodePath("../../../Model/Skeleton/Skeleton3D")
 
 [node name="UpperBody" type="BoneAttachment3D" parent="AnimationController/Root/LowerBody"]
-transform = Transform3D(1, -1.08108e-08, 8.67517e-08, 0, 0.992324, 0.123662, -8.74228e-08, -0.123662, 0.992324, 8.88178e-16, 0.154362, 0)
+transform = Transform3D(1, -1.08108e-08, 8.67517e-08, 0, 0.992324, 0.123662, -8.74228e-08, -0.123662, 0.992324, 1.77636e-15, 0.154362, 0)
 bone_name = "UpperBody"
 bone_idx = 4
 use_external_skeleton = true
 external_skeleton = NodePath("../../../../Model/Skeleton/Skeleton3D")
 
 [node name="Neck" type="BoneAttachment3D" parent="AnimationController/Root/LowerBody/UpperBody"]
-transform = Transform3D(1, -4.4409e-16, -7.10543e-15, 0, 0.998891, -0.0470728, 0, 0.0470728, 0.998892, -4.44089e-16, 0.251888, 1.49012e-08)
+transform = Transform3D(1, -4.4409e-16, -7.10543e-15, 0, 0.998891, -0.0470728, 0, 0.0470728, 0.998892, -1.11022e-15, 0.251888, 1.49012e-08)
 bone_name = "Neck"
 bone_idx = 5
 use_external_skeleton = true

project.godot

@@ -11,7 +11,7 @@ config_version=5
 [application]
 
 config/name="Inventory2"
-run/main_scene="res://scenes/game.tscn"
+run/main_scene="res://game.tscn"
 config/features=PackedStringArray("4.2", "C#", "GL Compatibility")
 config/icon="res://assets/icon.svg"
 

scenes/workshop.tscn

@@ -1,6 +1,5 @@
-[gd_scene load_steps=14 format=3 uid="uid://bwfuet1irfi17"]
+[gd_scene load_steps=13 format=3 uid="uid://bwfuet1irfi17"]
 
-[ext_resource type="PackedScene" uid="uid://dmd7w2r8s0x6y" path="res://player/player.tscn" id="1_cxvln"]
 [ext_resource type="Script" path="res://objects/Grid.cs" id="2_gstd0"]
 [ext_resource type="PackedScene" uid="uid://yvy5vvaqgxy8" path="res://objects/crate.tscn" id="2_j6a20"]
 [ext_resource type="Script" path="res://objects/Item.cs" id="3_01pgc"]
@@ -34,12 +33,6 @@ size = Vector2(10, 10)
 [node name="Sun" type="DirectionalLight3D" parent="."]
 transform = Transform3D(0.866025, 0, -0.5, 0.25, 0.866025, 0.433013, 0.433013, -0.5, 0.75, 0, 5, 0)
 
-[node name="Player" parent="." instance=ExtResource("1_cxvln")]
-
-[node name="OtherPlayer" parent="." instance=ExtResource("1_cxvln")]
-transform = Transform3D(-1, 0, 8.74228e-08, 0, 1, 0, -8.74228e-08, 0, -1, 2, 0.75, -4)
-IsLocal = false
-
 [node name="Crates" type="Node3D" parent="."]
 
 [node name="Crate1" parent="Crates" instance=ExtResource("2_j6a20")]

scripts/MultiplayerManager.cs

@@ -0,0 +1,81 @@
+public partial class MultiplayerManager : Node
+{
+	[Export] public Player LocalPlayer { get; set; }
+	[Export] public Node3D Players { get; set; }
+	[Export] public PackedScene PlayerScene { get; set; }
+
+	public event Action<Player> PlayerJoined;
+	public event Action<Player> PlayerLeft;
+
+	public override void _Ready()
+	{
+		Multiplayer.ConnectedToServer  += OnMultiplayerReady;
+		Multiplayer.ServerDisconnected += OnMultiplayerDisconnected;
+		Multiplayer.PeerConnected      += OnPeerConnected;
+		Multiplayer.PeerDisconnected   += OnPeerDisconnected;
+	}
+
+
+	public void Connect(string address, ushort port)
+	{
+		var peer = new ENetMultiplayerPeer();
+		peer.CreateClient(address, port);
+		Multiplayer.MultiplayerPeer = peer;
+	}
+
+	public bool CreateServer(ushort port)
+	{
+		var peer = new ENetMultiplayerPeer();
+		if (peer.CreateServer(port) == Error.Ok) {
+			Multiplayer.MultiplayerPeer = peer;
+			OnMultiplayerReady();
+			return true;
+		} else
+			return false;
+	}
+
+	public void Disconnect()
+		=> OnMultiplayerDisconnected();
+
+
+	void OnMultiplayerReady()
+	{
+		var localId = Multiplayer.GetUniqueId();
+		LocalPlayer.Name = localId.ToString();
+		LocalPlayer.SetMultiplayerAuthority(localId);
+
+		if (!Multiplayer.IsServer())
+			// Spawn players for all the other peers. This excludes the server,
+			// since `OnPeerConnected` will already be called for it on connecting.
+			foreach (var peerId in Multiplayer.GetPeers())
+				if (peerId != 1) OnPeerConnected(peerId);
+	}
+
+	void OnMultiplayerDisconnected()
+	{
+		LocalPlayer.Name = "Local";
+		foreach (var player in Players.GetChildren().Cast<Player>())
+			OnPeerDisconnected(player.PeerId);
+		Multiplayer.MultiplayerPeer.Close();
+		Multiplayer.MultiplayerPeer = null;
+	}
+
+
+	void OnPeerConnected(long peerId)
+	{
+		var player = PlayerScene.Instantiate<Player>();
+		player.SetMultiplayerAuthority((int)peerId);
+		player.Name = peerId.ToString();
+		player.IsLocal = false;
+		player.PeerId = (int)peerId;
+		Players.AddChild(player);
+		PlayerJoined?.Invoke(player);
+	}
+
+	void OnPeerDisconnected(long peerId)
+	{
+		var player = Players.GetNode<Player>(peerId.ToString());
+		PlayerLeft?.Invoke(player);
+		player.QueueFree();
+	}
+}

scripts/globals/GlobalUsings.cs

@@ -1,4 +1,5 @@
 global using System;
+global using System.Linq;
 global using Godot;
 global using Godot.Collections;
 global using static Godot.GD;

ui/MultiplayerMenu.cs

@@ -30,16 +30,18 @@ public partial class MultiplayerMenu : MarginContainer
 	[Export] public Label     PlayersLabel     { get; set; }
 	[Export] public Button    DisconnectButton { get; set; }
 
+	Game _game;
 	public override void _Ready()
 	{
+		_game = GetNode<Game>("/root/Game");
 		PortDisplay.AddThemeColorOverride("font_uneditable_color", PortDisplay.GetThemeColor("font_color"));
 
 		Multiplayer.ConnectedToServer  += () => UpdateStatus(Status.Connected);
 		Multiplayer.ConnectionFailed   += () => UpdateStatus(Status.ConnectionFailed);
 		Multiplayer.ServerDisconnected += () => UpdateStatus(Status.Disconnected);
 
-		Multiplayer.PeerConnected    += (_) => UpdatePlayerCount();
+		_game.MultiplayerManager.PlayerJoined += (_) => UpdatePlayerCount();
-		Multiplayer.PeerDisconnected += (_) => UpdatePlayerCount();
+		_game.MultiplayerManager.PlayerLeft   += (_) => UpdatePlayerCount();
 	}
 
 	void UpdateStatus(Status status)
@@ -79,7 +81,7 @@ public partial class MultiplayerMenu : MarginContainer
 			< Status.Connecting => "Singleplayer",
 			  Status.Connecting => "??? Players",
 			> Status.Connecting => ((Func<string>)(() => {
-				var players = Multiplayer.GetPeers().Length + 1;
+				var players = _game.MultiplayerManager.Players.GetChildCount();
 				return $"{players} {(players != 1 ? "Players" : "Player")}";
 			}))(),
 		};
@@ -97,32 +99,24 @@ public partial class MultiplayerMenu : MarginContainer
 	{
 		var address = AddressInput.Text;
 		if (address == "") address = AddressInput.PlaceholderText;
-		var port = RoundToInt(PortInput.Value);
+		var port = (ushort)RoundToInt(PortInput.Value);
-
+		_game.MultiplayerManager.Connect(address, port);
-		var peer = new ENetMultiplayerPeer();
-		peer.CreateClient(address, port);
-		Multiplayer.MultiplayerPeer = peer;
 		UpdateStatus(Status.Connecting);
 	}
 
 	public void OnHostPressed()
 	{
-		var port = RoundToInt(PortInput.Value);
+		var port = (ushort)RoundToInt(PortInput.Value);
+		if (_game.MultiplayerManager.CreateServer(port)) {
 			PortDisplay.Text = port.ToString();
-
-		var peer = new ENetMultiplayerPeer();
-		if (peer.CreateServer(port) == Error.Ok) {
-			Multiplayer.MultiplayerPeer = peer;
 			UpdateStatus(Status.Hosting);
-		} else {
+		} else
 			UpdateStatus(Status.HostingFailed);
 	}
-	}
 
 	public void OnDisconnectPressed()
 	{
-		Multiplayer.MultiplayerPeer.Close();
+		_game.MultiplayerManager.Disconnect();
-		Multiplayer.MultiplayerPeer = null;
 		UpdateStatus(Status.Disconnected);
 	}
 }