bogies and exported properties

.vscode/settings.json

@@ -1,4 +1,5 @@
 {
     "editor.formatOnSave": true,
-    "editor.formatOnType": true
+    "editor.formatOnType": true,
+    "vscode-neovim.neovimExecutablePaths.linux": "/usr/bin/nvim"
 }

scenes/Bogie.tscn

@@ -0,0 +1,9 @@
+[gd_scene format=2]
+
+[node name="Bogey" type="Spatial"]
+
+[node name="CSGBox" type="CSGBox" parent="."]
+transform = Transform( 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0.2, 0 )
+width = 0.9
+height = 0.4
+depth = 1.1

scenes/Main.tscn

@@ -17,3 +17,6 @@ transform = Transform( 0.515898, 0.606099, -0.605386, -0.393123, 0.795389, 0.461
 _speed = 0.5
 
 [node name="Railway" parent="." instance=ExtResource( 2 )]
+RailWidth = 0.0
+RailHeight = 0.0
+RailGauge = 0.0

scenes/Rail.tscn

@@ -0,0 +1,25 @@
+[gd_scene load_steps=2 format=2]
+
+[sub_resource type="Curve3D" id=1]
+_data = {
+"points": PoolVector3Array(  ),
+"tilts": PoolRealArray(  )
+}
+
+[node name="Rail" type="Spatial"]
+
+[node name="Path" type="Path" parent="."]
+curve = SubResource( 1 )
+
+[node name="CSGPolygon" type="CSGPolygon" parent="."]
+polygon = PoolVector2Array( -0.383256, -0.00220253, -0.383256, 1.0066, 0.383256, 1.00219, 0.383256, -0.00220253 )
+mode = 2
+path_node = NodePath("../Path")
+path_interval_type = 0
+path_interval = 1.0
+path_simplify_angle = 0.0
+path_rotation = 2
+path_local = false
+path_continuous_u = true
+path_u_distance = 1.0
+path_joined = false

scenes/Railway.tscn

@@ -11,17 +11,17 @@ _data = {
 
 [node name="Railway" type="Spatial"]
 script = ExtResource( 1 )
+RailWidth = 0.05
+RailHeight = 0.1
+RailGauge = 0.8
 _railPaths = [ NodePath("L"), NodePath("R") ]
 _centreLine = NodePath("Centreline")
-_railWidth = 0.07
-_railHeight = 0.12
-_railGauge = 0.8
 
 [node name="Centreline" type="Path" parent="."]
 curve = SubResource( 1 )
 
 [node name="L" type="CSGPolygon" parent="."]
-polygon = PoolVector2Array( -0.47, 0, -0.47, 0.12, -0.33, 0.12, -0.33, 0 )
+polygon = PoolVector2Array( -0.45, 0, -0.45, 0.1, -0.35, 0.1, -0.35, 0 )
 mode = 2
 path_node = NodePath("../Centreline")
 path_interval_type = 0
@@ -34,7 +34,7 @@ path_u_distance = 1.0
 path_joined = false
 
 [node name="R" type="CSGPolygon" parent="."]
-polygon = PoolVector2Array( 0.33, 0, 0.33, 0.12, 0.47, 0.12, 0.47, 0 )
+polygon = PoolVector2Array( 0.35, 0, 0.35, 0.1, 0.45, 0.1, 0.45, 0 )
 mode = 2
 path_node = NodePath("../Centreline")
 path_interval_type = 0

scenes/Train.tscn

@@ -1,11 +1,9 @@
-[gd_scene load_steps=2 format=2]
+[gd_scene load_steps=3 format=2]
 
 [ext_resource path="res://scripts/Train.cs" type="Script" id=1]
+[ext_resource path="res://scenes/TrainCar.tscn" type="PackedScene" id=2]
 
 [node name="Train" type="Spatial"]
 script = ExtResource( 1 )
 
-[node name="CSGBox" type="CSGBox" parent="."]
+[node name="Train Car" parent="." instance=ExtResource( 2 )]
-width = 1.0
-height = 1.0
-depth = 4.0

scenes/TrainCar.tscn

@@ -0,0 +1,21 @@
+[gd_scene load_steps=3 format=2]
+
+[ext_resource path="res://scripts/TrainCar.cs" type="Script" id=1]
+[ext_resource path="res://scenes/Bogie.tscn" type="PackedScene" id=2]
+
+[node name="Train Car" type="Spatial"]
+script = ExtResource( 1 )
+_boxNode = NodePath("CSGBox")
+_bogiePaths = [ NodePath("Bogie"), NodePath("Bogie2") ]
+
+[node name="CSGBox" type="CSGBox" parent="."]
+transform = Transform( 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0 )
+width = 1.0
+height = 1.0
+depth = 8.0
+
+[node name="Bogie" parent="." instance=ExtResource( 2 )]
+transform = Transform( 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, -2 )
+
+[node name="Bogie2" parent="." instance=ExtResource( 2 )]
+transform = Transform( 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 2 )

scripts/Railway.cs

@@ -11,12 +11,51 @@ public class Railway : Node
     [Export]
     private NodePath _centreLine;
 
-    [Export]
+
     private float _railWidth;
-    [Export]
     private float _railHeight;
+    private float _railGauge;
+
     [Export]
-    private float _railGauge = 1.0f;
+    private float RailWidth
+    {
+        get => _railWidth;
+        set
+        {
+            _railWidth = value;
+            if (Engine.EditorHint)
+            {
+                SetRailCrossSection();
+            }
+        }
+    }
+    [Export]
+    private float RailHeight
+    {
+        get => _railHeight;
+        set
+        {
+            _railHeight = value;
+            if (Engine.EditorHint)
+            {
+                SetRailCrossSection();
+            }
+        }
+    }
+
+    [Export]
+    private float RailGauge
+    {
+        get => _railGauge;
+        set
+        {
+            _railGauge = value;
+            if (Engine.EditorHint)
+            {
+                SetRailCrossSection();
+            }
+        }
+    }
 
     private Path _path = null;
     private Path Path
@@ -40,6 +79,7 @@ public class Railway : Node
     // Called when the node enters the scene tree for the first time.
     public override void _Ready()
     {
+
     }
 
     private void SetRailCrossSection()
@@ -53,10 +93,10 @@ public class Railway : Node
         {
             var rail = GetNode<CSGPolygon>(_railPaths[i]);
 
-            float w = _railWidth;
+            float w = RailWidth;
-            float h = _railHeight;
+            float h = RailHeight;
             // horizontal offset of rail from centreline
-            float c = (-.5f + i) * _railGauge;
+            float c = (-.5f + i) * RailGauge;
 
             var polygon = new Vector2[4];
             polygon[0] = new Vector2(c - w, 0);
@@ -69,10 +109,7 @@ public class Railway : Node
 
     public override void _Process(float delta)
     {
-        if (Engine.EditorHint)
+
-        {
-            SetRailCrossSection();
-        }
     }
 
     public void AddPathFollower(PathFollow pathFollow)

scripts/TrainCar.cs

@@ -0,0 +1,72 @@
+using Godot;
+using System;
+
+[Tool]
+public class TrainCar : Spatial
+{
+    public float Length => Box.Depth;
+
+    [Export]
+    private NodePath _boxNode;
+
+    [Export]
+    private NodePath[] _bogiePaths;
+
+    [Export]
+    private float Wheelbase
+    {
+        get => _wheelbase;
+        set
+        {
+            _wheelbase = value;
+            if (Engine.EditorHint)
+            {
+                SetBogeyPositions();
+            }
+        }
+    }
+    private float _wheelbase;
+
+    private readonly Spatial[] _bogies = new Spatial[2];
+
+    private CSGBox _box;
+    private CSGBox Box
+    {
+        get
+        {
+            if (_box == null)
+            {
+                _box = GetNode<CSGBox>(_boxNode);
+            }
+            return _box;
+        }
+    }
+
+    public override void _Ready()
+    {
+
+    }
+
+    public override void _Process(float delta)
+    {
+    }
+
+    private void SetBogeyPositions()
+    {
+
+        if (Wheelbase > Length)
+            throw new Exception("wheelbase cannot be longer than car length");
+
+        if (_bogiePaths.Length != 2)
+            throw new Exception("_bogeyPaths should be of length 2");
+
+        for (int i = 0; i < 2; i++)
+        {
+            _bogies[i] = GetNode<Spatial>(_bogiePaths[i]);
+        }
+
+        var axis = Vector3.Forward * Wheelbase;
+        _bogies[0].Translation = axis * 0.5f;
+        _bogies[1].Translation = axis * -0.5f;
+    }
+}