Change the camera rotation origin - the math is still wrong

Author: pzgulyas

Source/Contrib/TrackViewer/SceneViewer.cs

@@ -56,7 +56,7 @@ public class SceneViewer
         internal StaticShape SelectedObject;
         internal Orts.Formats.Msts.WorldObject SelectedWorldObject;
         Viewer Viewer;
-        ViewerCamera Camera;
+        OrbitingCamera Camera;
 
         /// <summary>The command-line arguments</summary>
         private string[] CommandLineArgs;
@@ -138,7 +138,7 @@ public void Update(GameTime gameTime)
             Viewer = Viewer ?? TrackViewer.RenderProcess?.Viewer;
             if (Viewer == null)
                 return;
-            Camera = Camera ?? Viewer.ViewerCamera;
+            Camera = Camera ?? Viewer.OrbitingCamera;
 
             Viewer.EditorShapes.MouseCrosshairEnabled = true;
 
@@ -216,7 +216,7 @@ public async Task SetCameraLocation()
                 break;
             }
             mouseLocation.Location.Y = elevatedLocation + 15;
-            TrackViewer.RenderProcess.Viewer.ViewerCamera.SetLocation(mouseLocation);
+            TrackViewer.RenderProcess.Viewer.OrbitingCamera.SetLocation(mouseLocation);
         }
 
         void SelectedObjectChanged()

Source/RunActivity/Viewer3D/Cameras.cs

@@ -778,16 +778,17 @@ protected override void ZoomIn(float speed)
         }
     }
 
-    public class ViewerCamera : FreeRoamCamera
+    public class OrbitingCamera : FreeRoamCamera
     {
-        Vector3 RotationOrigin;
-        Vector3 RotationDirection;
-        WorldLocation RotationLocation;
-        float RotationRadius;
-        float RotationReferenceAngleX;
-        float RotationReferenceAngleY;
-
-        public ViewerCamera(Viewer viewer)
+        Vector3 StoredOrigin;
+        Vector3 StoredDirection = Vector3.UnitZ;
+        Vector3 StoredForward = Vector3.UnitZ;
+        WorldLocation StoredLocation;
+        float StoredRadius;
+        float StoredAngleX;
+        float StoredAngleY;
+
+        public OrbitingCamera(Viewer viewer)
             : base(viewer)
         {
         }
@@ -827,44 +828,40 @@ public override void RotateByMouse()
             RotationXRadians = MathHelper.WrapAngle(RotationXRadians + GetMouseDelta(UserInput.MouseMoveY));
             RotationYRadians = MathHelper.WrapAngle(RotationYRadians + GetMouseDelta(UserInput.MouseMoveX));
 
-            // Method 1
-            //var deltaAngleX = MathHelper.WrapAngle(GetMouseDelta(UserInput.MouseMoveY));
-            //var deltaAngleY = MathHelper.WrapAngle(GetMouseDelta(UserInput.MouseMoveX));
-            //var direction = Vector3.Normalize(XnaLocation(CameraWorldLocation) - RotationOrigin);
-            //var transform = Matrix.CreateFromYawPitchRoll(-deltaAngleY, -deltaAngleX, 0);
-            //var newLocation = RotationOrigin + RotationRadius * Vector3.Transform(direction, transform);
-            //newLocation.Z *= -1;
-            //var newWorldLocation = CameraWorldLocation;
-            //newWorldLocation.Location = newLocation;
+            var deltaAngleX = MathHelper.WrapAngle(RotationXRadians - StoredAngleX);
+            var deltaAngleY = MathHelper.WrapAngle(RotationYRadians - StoredAngleY);
 
-            // Method 2
-            //var deltaAngleX = MathHelper.WrapAngle(RotationXRadians - RotationReferenceAngleX);
-            //var deltaAngleY = MathHelper.WrapAngle(RotationYRadians - RotationReferenceAngleY);
-            //var transform = Matrix.CreateFromYawPitchRoll(-deltaAngleY, -deltaAngleX, 0);
-            //var newLocation = RotationOrigin + RotationRadius * Vector3.Transform(RotationDirection, transform);
+            var dax = StoredForward.Z * deltaAngleX;
+            var daz = StoredForward.X * deltaAngleX;
+            var transform = Matrix.CreateRotationX(dax);
+            transform *= Matrix.CreateRotationZ(daz);
+            transform *= Matrix.CreateRotationY(-deltaAngleY);
 
-            // Method 3
-            //var deltaAngleX = MathHelper.WrapAngle(RotationXRadians);
-            //var deltaAngleY = MathHelper.WrapAngle(RotationYRadians);
-            //var transform = Matrix.CreateFromYawPitchRoll(-deltaAngleY, -deltaAngleX, 0);
-            //var newLocation = RotationOrigin + RotationRadius * Vector3.Transform(Vector3.UnitZ, transform);
+            // FIXME: The math is still wrong here somewhere...
 
-            //newLocation.Z *= -1;
-            //var newWorldLocation = RotationLocation;
-            //newWorldLocation.Location = newLocation;
+            var newWorldLocation = StoredLocation;
+            newWorldLocation.Location = StoredOrigin + StoredRadius * Vector3.Transform(StoredDirection, transform);
+            newWorldLocation.Location.Z *= -1;
 
-            //SetLocation(newWorldLocation);
+            cameraLocation = newWorldLocation;
         }
 
         public void StoreRotationOrigin(Vector3 rotationOrigin)
         {
-            RotationOrigin = Viewer.TerrainPoint;
-            RotationLocation = CameraWorldLocation;
-            RotationDirection = XnaLocation(CameraWorldLocation) - RotationOrigin;
-            RotationRadius = RotationDirection.Length();
-            RotationDirection = Vector3.Normalize(RotationDirection);
-            RotationReferenceAngleX = MathHelper.WrapAngle(RotationXRadians);
-            RotationReferenceAngleY = MathHelper.WrapAngle(RotationYRadians);
+            StoredOrigin = Viewer.TerrainPoint;
+            StoredLocation = CameraWorldLocation;
+            StoredDirection = XnaLocation(CameraWorldLocation) - StoredOrigin;
+            StoredRadius = StoredDirection.Length();
+            StoredDirection = Vector3.Normalize(StoredDirection);
+            StoredAngleX = MathHelper.WrapAngle(RotationXRadians);
+            StoredAngleY = MathHelper.WrapAngle(RotationYRadians);
+            StoredForward = xnaView.Forward;
+        }
+
+        public void SetOrientation(float rotationXRadians, float rotationYRadians)
+        {
+            RotationXRadians = rotationXRadians;
+            RotationYRadians = rotationYRadians;
         }
 
         public void PanByMouse()

Source/RunActivity/Viewer3D/Viewer.cs

@@ -135,7 +135,7 @@ public class Viewer
         public BrakemanCamera BrakemanCamera { get; private set; } // Camera 6
         public List<FreeRoamCamera> FreeRoamCameraList = new List<FreeRoamCamera>();
         public FreeRoamCamera FreeRoamCamera { get { return FreeRoamCameraList[0]; } } // Camera 8
-        public ViewerCamera ViewerCamera { get; private set; }
+        public OrbitingCamera OrbitingCamera { get; private set; }
 
         /// <summary>
         /// Activate the 2D or 3D cab camera depending on the current player preference.
@@ -176,7 +176,7 @@ void CameraActivate()
                 if (PlayerLocomotive != null)
                     FrontCamera.Activate();
                 else
-                    ViewerCamera.Activate();
+                    OrbitingCamera.Activate();
             }
             else
                 Camera.Activate();
@@ -324,7 +324,7 @@ public Viewer(Simulator simulator, Orts.Viewer3D.Processes.Game game)
             WellKnownCameras.Add(SpecialTracksideCamera = new SpecialTracksideCamera(this));
             FreeRoamCameraList.Add(new FreeRoamCamera(this, FrontCamera)); // Any existing camera will suffice to satisfy .Save() and .Restore()
             WellKnownCameras.Add(FreeRoamCamera);
-            WellKnownCameras.Add(ViewerCamera = new ViewerCamera(this));
+            WellKnownCameras.Add(OrbitingCamera = new OrbitingCamera(this));
             WellKnownCameras.Add(ThreeDimCabCamera = new ThreeDimCabCamera(this));
 
             string ORfilepath = System.IO.Path.Combine(Simulator.RoutePath, "OpenRails");