#16 Udemy 2.5D RPG Enemies patrolling

Udemy25dRpg/Scenes/Characters/Character.cs → Udemy25dRpg/Scenes/Characters/CharacterBase.cs

@@ -10,6 +10,12 @@ public abstract partial class CharacterBase : CharacterBody3D
     [Export, ExportGroup("Required Nodes")]
     public AnimatedSprite3D AnimatedSprite3DNode { get; protected set; }
 
+    [Export, ExportGroup("AI Nodes")]
+    public Path3D PathNode { get; private set; }
+
+    [Export, ExportGroup("AI Nodes")]
+    public NavigationAgent3D NavigationAgentNode { get; private set; }
+
     public Vector2 Direction { get; protected set; } = Vector2.Zero;
 
     public void FlipSprite()

Udemy25dRpg/Scenes/Characters/Enemy/Enemy.tscn

@@ -1,4 +1,4 @@
-[gd_scene load_steps=105 format=3 uid="uid://26cy6bbsdt37"]
+[gd_scene load_steps=107 format=3 uid="uid://26cy6bbsdt37"]
 
 [ext_resource type="Texture2D" uid="uid://ckonrd67f8enh" path="res://Assets/Sprites/Characters/Enemy Knight/Attack/0_Demons_of_Darkness_Slashing_000.png" id="1_gty22"]
 [ext_resource type="Texture2D" uid="uid://cjdjjbuattvtu" path="res://Assets/Sprites/Characters/Enemy Knight/Idle/0_Demons_of_Darkness_Idle_000.png" id="1_le6bp"]
@@ -102,6 +102,8 @@
 [ext_resource type="Texture2D" uid="uid://b4pv0ny4xgeme" path="res://Assets/Sprites/Characters/Enemy Knight/TakeHit/0_Demons_of_Darkness_Hurt_011.png" id="99_5kr26"]
 [ext_resource type="PackedScene" uid="uid://chsjgdc42gn10" path="res://Scenes/Characters/StateMachine.tscn" id="101_svyoj"]
 [ext_resource type="Script" path="res://Scenes/Characters/Enemy/EnemyIdleState.cs" id="102_d6q6i"]
+[ext_resource type="Script" path="res://Scenes/Characters/Enemy/EnemyReturnState.cs" id="103_k2nhi"]
+[ext_resource type="Script" path="res://Scenes/Characters/Enemy/EnemyPatrolState.cs" id="104_0iq21"]
 
 [sub_resource type="SpriteFrames" id="SpriteFrames_nl2d3"]
 animations = [{
@@ -432,27 +434,37 @@ animations = [{
 radius = 0.549619
 height = 1.29953
 
-[node name="Enemy" type="CharacterBody3D" node_paths=PackedStringArray("StateMachineNode", "AnimatedSprite3DNode")]
+[node name="Enemy" type="CharacterBody3D" node_paths=PackedStringArray("StateMachineNode", "AnimatedSprite3DNode", "NavigationAgentNode")]
 collision_layer = 4
 collision_mask = 7
 floor_max_angle = 1.55334
 floor_snap_length = 100.0
 script = ExtResource("1_tph2b")
 StateMachineNode = NodePath("StateMachine")
 AnimatedSprite3DNode = NodePath("AnimatedSprite3D")
+NavigationAgentNode = NodePath("NavigationAgent3D")
 
 [node name="AnimatedSprite3D" type="AnimatedSprite3D" parent="."]
 pixel_size = 0.0025
 sprite_frames = SubResource("SpriteFrames_nl2d3")
-animation = &"Idle"
+animation = &"Move"
 
 [node name="StateMachine" parent="." node_paths=PackedStringArray("CurrentState", "PossibleStates") instance=ExtResource("101_svyoj")]
 CurrentState = NodePath("IdleState")
-PossibleStates = [NodePath("IdleState"), NodePath(""), NodePath("")]
+PossibleStates = [NodePath("IdleState"), NodePath("ReturnState"), NodePath("PatrolState")]
 
 [node name="IdleState" type="Node" parent="StateMachine"]
 script = ExtResource("102_d6q6i")
 
+[node name="ReturnState" type="Node" parent="StateMachine"]
+script = ExtResource("103_k2nhi")
+
+[node name="PatrolState" type="Node" parent="StateMachine"]
+script = ExtResource("104_0iq21")
+
 [node name="CollisionShape3D" type="CollisionShape3D" parent="."]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -0.0016498, -0.0394009, 0.0142541)
 shape = SubResource("CapsuleShape3D_vahjm")
+
+[node name="NavigationAgent3D" type="NavigationAgent3D" parent="."]
+debug_enabled = true

Udemy25dRpg/Scenes/Characters/Enemy/EnemyIdleState.cs

@@ -1,6 +1,3 @@
-using Godot;
-using System;
-
 namespace Udemy25dRpg.Scenes.Characters.Enemy;
 
 public partial class EnemyIdleState : StateMachineStateBase
@@ -9,4 +6,14 @@ protected override void EnterState()
     {
         _characterNode.AnimatedSprite3DNode.Play(nameof(Enemy.EnemyAnimations.Idle));
     }
+
+    public override void _PhysicsProcess(double delta)
+    {
+        base._PhysicsProcess(delta);
+
+        if (_characterNode.NavigationAgentNode.IsNodeReady())
+        {
+            _characterNode.StateMachineNode.SwitchState<EnemyReturnState>();
+        }
+    }
 }

Udemy25dRpg/Scenes/Characters/Enemy/EnemyPatrolState.cs

@@ -0,0 +1,31 @@
+namespace Udemy25dRpg.Scenes.Characters.Enemy;
+
+public partial class EnemyPatrolState : StateMachineStateBase
+{
+    private int _pathNodeIndex = 0;
+
+    protected override void EnterState()
+    {
+        _characterNode.AnimatedSprite3DNode.Play(nameof(Enemy.EnemyAnimations.Move));
+    }
+
+    public override void _PhysicsProcess(double delta)
+    {
+        base._PhysicsProcess(delta);
+
+        if (_characterNode.NavigationAgentNode.IsNodeReady() && _characterNode.NavigationAgentNode.IsNavigationFinished())
+        {
+            if (_pathNodeIndex >= _characterNode.PathNode.Curve.PointCount)
+            {
+                _pathNodeIndex = 0;
+            }
+
+            _characterNode.NavigationAgentNode.TargetPosition =
+                _characterNode.PathNode.Curve.GetPointPosition(_pathNodeIndex++) +
+                _characterNode.PathNode.GlobalPosition;
+        }
+
+        _characterNode.Velocity = _characterNode.GlobalPosition.DirectionTo(_characterNode.NavigationAgentNode.TargetPosition);
+        _characterNode.MoveAndSlide();
+    }
+}

Udemy25dRpg/Scenes/Characters/Enemy/EnemyReturnState.cs

@@ -0,0 +1,35 @@
+using Godot;
+
+namespace Udemy25dRpg.Scenes.Characters.Enemy;
+
+public partial class EnemyReturnState : StateMachineStateBase
+{
+    private Vector3 _destination;
+
+    public override void _Ready()
+    {
+        base._Ready();
+
+        _destination = 
+            _characterNode.PathNode.Curve.GetPointPosition(0) +
+            _characterNode.PathNode.GlobalPosition;
+    }
+
+    protected override void EnterState()
+    {
+        _characterNode.AnimatedSprite3DNode.Play(nameof(Enemy.EnemyAnimations.Move));
+        _characterNode.NavigationAgentNode.TargetPosition = _destination;
+    }
+
+    public override void _PhysicsProcess(double delta)
+    {
+        if (_characterNode.NavigationAgentNode.IsNavigationFinished())
+        {
+            _characterNode.StateMachineNode.SwitchState<EnemyPatrolState>();
+            return;
+        }
+
+        _characterNode.Velocity = _characterNode.GlobalPosition.DirectionTo(_destination);
+        _characterNode.MoveAndSlide();
+    }
+}