adjust orbit speed

scenes/Main.tscn

@@ -14,3 +14,4 @@ transform = Transform( 0.515898, 0.606099, -0.605386, -0.393123, 0.795389, 0.461
 transform = Transform( 0.856869, 0.3292, -0.396741, 0.0949996, 0.655565, 0.749139, 0.506706, -0.679604, 0.53046, -0.599122, 0, 0 )
 SemiMajorAxis = 6.166
 Eccentricity = 0.239
+_speed = 0.877

scenes/OrbitCamera.tscn

@@ -4,6 +4,8 @@
 
 [node name="OrbitCamera" type="Spatial"]
 script = ExtResource( 1 )
+_zoomSensitivity = 50.0
+_cameraPath = NodePath("Camera")
 
 [node name="Camera" type="Camera" parent="."]
 transform = Transform( 1, 0, 0, 0, 0.964146, 0.265371, 0, -0.265371, 0.964146, 0, 2.21115, 9.48434 )

scripts/OrbitCamera.cs

@@ -4,7 +4,25 @@ using System;
 public class OrbitCamera : Spatial
 {
     [Export]
-    private float _sensitivity = 200f;
+    private float _lookSensitivity = 200f;
+
+    [Export]
+    private float _zoomSensitivity = 10f;
+
+    [Export]
+    private NodePath _cameraPath;
+    private Camera _camera = null;
+    private Camera Camera
+    {
+        get
+        {
+            if (_camera == null)
+            {
+                _camera = GetNode<Camera>(_cameraPath);
+            }
+            return _camera;
+        }
+    }
 
     private Vector2 _rotation;
     private bool _canRotate = false;
@@ -24,7 +42,8 @@ public class OrbitCamera : Spatial
     public override void _Process(float delta)
     {
         Rotation = Vector3.Zero;
-        var sensitivity = -1f / _sensitivity;
+        var sensitivity = -1f / _lookSensitivity;
+
         Rotate(Vector3.Right, _rotation.y * sensitivity);
         Rotate(Vector3.Up, _rotation.x * sensitivity);
     }
@@ -32,9 +51,23 @@ public class OrbitCamera : Spatial
     // left click to drag
     private void HandleMouseButton(InputEventMouseButton mouseButton)
     {
-        if (mouseButton.ButtonIndex != (int)ButtonList.Left) return;
+        switch ((ButtonList)mouseButton.ButtonIndex)
+        {
+            case ButtonList.Left:
+                _canRotate = mouseButton.Pressed;
+                break;
+            case ButtonList.WheelUp:
+                Zoom(-1);
+                break;
+            case ButtonList.WheelDown:
+                Zoom(1);
+                break;
+        }
+    }
 
-        _canRotate = mouseButton.Pressed;
+    private void Zoom(float amount)
+    {
+        Camera.Fov += amount * _zoomSensitivity / Camera.Fov;
     }
 
     private void HandleMouseMovement(InputEventMouseMotion mouseMotion)

scripts/orbits/OrbitSystem.cs

@@ -134,9 +134,12 @@ public class OrbitSystem : Node, IMassive, ILocation
 
     private float _time = 0;
 
+    [Export]
+    private float _speed = 3f;
+
     public override void _Process(float delta)
     {
-        _time += delta * 3f;
+        _time += delta * _speed;
         InvalidateGeometry();
     }