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--- 0.8.3:interaction [2020/11/17 18:53] – external edit 127.0.0.1
+++ 0.8.3:interaction [2022/04/20 15:45] (current) – [Classic Camera Mouse Movement] admin
@@ Line 85: / Line 85: @@
 Another solution is to include rotation behaviour in each object related mouse-move event, or to use TGorillaInputController with global mouse hooks ([[inputpolling|Input Polling]]).
+==== Classic Camera Mouse Movement  ====
+Very often users want to implement  simple camera movement controlled by mouse.
+Here is a simple example how to move your camera in your scene.
+It expects a simple component setup before it works.
+  - Put A TDummy onto your viewport
+  - Put A TCamera / TGorillaCamera inside this TDummy component
+  - Position the TCamera/TGorillaCamera component at a position like (0.0, -2.5, -10)
+  - Set TCamera/TGorillaCamera "Target" to the Dummy
+  - Do not forget to set the "Camera" as active in your viewport
+  - Do not forget to disable "UseDesignCamera"
+Then you can create 4 events by the event editor in your IDE object inspector with the following code:
+<file pascal>
+var FMove : Boolean;
+    FLastPos : TPointF;
+    FSpeed : Single = 0.1;
+procedure TGameWin.GorillaViewport1MouseDown(Sender: TObject;
+  Button: TMouseButton; Shift: TShiftState; X, Y: Single);
+begin
+  /// allow camera movement
+  FMove := true;
+  /// store the current mouse position to detect the pixel movement
+  FLastPos := PointF(X, Y);
+end;
+procedure TGameWin.GorillaViewport1MouseMove(Sender: TObject;
+  Shift: TShiftState; X, Y: Single);
+var LDiff : TPointF;
+    LDir  : TPoint3D;
+begin
+  /// if mouse was not down - skip camera movement here
+  if not FMove then
+  begin
+    FLastPos := PointF(X, Y);
+    Exit;
+  end;
+  /// compute the offset to the last pixel position
+  LDiff := PointF(X, Y) - FLastPos;
+  if ssRight in Shift then
+  begin
+    /// rotate camera on right mouse button down
+    Dummy1.RotationAngle.Y := Dummy1.RotationAngle.Y + LDiff.X;
+  end
+  else if ssLeft in Shift then
+  begin
+    /// move camera in view direction if left mouse button is down
+    LDir := TPoint3D.Zero;
+    /// at first we apply the left-side direction
+    LDir := LDir + TPoint3D(GorillaCamera1.AbsoluteLeft) * (LDiff.X * FSpeed);
+    /// then we apply the forward direction
+    LDir := LDir + TPoint3D(GorillaCamera1.AbsoluteDirection) * (LDiff.Y * FSpeed);
+    /// we move the parent dummy, not the camera itself!
+    /// simply by adding our direction vector to the current dummy position
+    Dummy1.Position.Point := Dummy1.Position.Point + LDir;
+  end;
+  FLastPos := PointF(X, Y);
+end;
+procedure TGameWin.GorillaViewport1MouseUp(Sender: TObject;
+  Button: TMouseButton; Shift: TShiftState; X, Y: Single);
+begin
+  FLastPos := PointF(X, Y);
+  FMove := false;
+end;
+procedure TGameWin.GorillaViewport1MouseWheel(Sender: TObject;
+  Shift: TShiftState; WheelDelta: Integer; var Handled: Boolean);
+begin
+  if WheelDelta < 0 then
+    GorillaCamera1.Position.Z := GorillaCamera1.Position.Z - 0.5
+  else
+    GorillaCamera1.Position.Z := GorillaCamera1.Position.Z + 0.5;
+  Handled := true;
+end;
+</file>
 ==== On components ====