some fixes

src/3d/qgscameracontroller.cpp

@@ -375,18 +375,7 @@ void QgsCameraController::onPositionChanged( Qt3DInput::QMouseEvent *mouse )
   mMousePos = QPoint( mouse->x(), mouse->y() );
 }
 
-void QgsCameraController::onPositionChangedFlyNavigation( Qt3DInput::QMouseEvent *mouse )
-{
-  if ( !mMousePressed )
-    return;
-  int dx = mouse->x() - mMousePos.x();
-  int dy = mouse->y() - mMousePos.y();
-  float diffPitch = 0.2f * dy;
-  float diffYaw = - 0.2f * dx;
-  rotateCamera( diffPitch, diffYaw );
-  updateCameraFromPose( false );
-  mMousePos = QPoint( mouse->x(), mouse->y() );
-}
+
 
 void QgsCameraController::zoom( float factor )
 {
@@ -410,16 +399,18 @@ void QgsCameraController::onMousePressed( Qt3DInput::QMouseEvent *mouse )
 {
   Q_UNUSED( mouse )
   mKeyboardHandler->setFocus( true );
-  if ( mouse->button() == Qt3DInput::QMouseEvent::Buttons::LeftButton )
+  if ( mouse->button() == Qt3DInput::QMouseEvent::LeftButton || mouse->button() == Qt3DInput::QMouseEvent::RightButton || mouse->button() == Qt3DInput::QMouseEvent::MiddleButton )
   {
     mMousePos = QPoint( mouse->x(), mouse->y() );
+    mPressedButton = mouse->button();
     mMousePressed = true;
   }
 }
 
 void QgsCameraController::onMouseReleased( Qt3DInput::QMouseEvent *mouse )
 {
   Q_UNUSED( mouse )
+  mPressedButton = Qt3DInput::QMouseEvent::NoButton;
   mMousePressed = false;
 }
 
@@ -531,6 +522,31 @@ void QgsCameraController::onKeyPressedFlyNavigation( Qt3DInput::QKeyEvent *event
   moveCameraPositionBy( cameraPosDiff );
 }
 
+void QgsCameraController::onPositionChangedFlyNavigation( Qt3DInput::QMouseEvent *mouse )
+{
+  if ( !mMousePressed )
+    return;
+  double dx = mouse->x() - mMousePos.x();
+  double dy = mouse->y() - mMousePos.y();
+  if ( mPressedButton ==  Qt3DInput::QMouseEvent::LeftButton || mPressedButton ==  Qt3DInput::QMouseEvent::MiddleButton )
+  {
+    float diffPitch = 0.2f * dy;
+    float diffYaw = - 0.2f * dx;
+    rotateCamera( diffPitch, diffYaw );
+    updateCameraFromPose( false );
+  }
+  else if ( mPressedButton ==  Qt3DInput::QMouseEvent::RightButton )
+  {
+    QVector3D cameraUp = mCamera->upVector().normalized();
+    QVector3D cameraFront = ( QVector3D( mCameraPose.centerPoint().x(), mCameraPose.centerPoint().y(), mCameraPose.centerPoint().z() ) - mCamera->position() ).normalized();
+    QVector3D cameraLeft = QVector3D::crossProduct( cameraUp, cameraFront );
+    QVector3D cameraPosDiff = dx / mViewport.width() * cameraLeft + dy / mViewport.height() * cameraUp;
+    moveCameraPositionBy( 5.0 * mCameraMovementSpeed * cameraPosDiff );
+  }
+
+  mMousePos = QPoint( mouse->x(), mouse->y() );
+}
+
 void QgsCameraController::onKeyReleased( Qt3DInput::QKeyEvent *event )
 {
   Q_UNUSED( event )

src/3d/qgscameracontroller.h

@@ -21,6 +21,7 @@
 #include <QPointer>
 #include <QRect>
 #include <Qt3DCore/QEntity>
+#include <Qt3DInput/QMouseEvent>
 
 namespace Qt3DInput
 {
@@ -221,6 +222,7 @@ class _3D_EXPORT QgsCameraController : public Qt3DCore::QEntity
     //! Last mouse position recorded
     QPoint mMousePos;
     bool mMousePressed = false;
+    Qt3DInput::QMouseEvent::Buttons mPressedButton = Qt3DInput::QMouseEvent::Buttons::NoButton;
 
     //! Delegates mouse events to the attached MouseHandler objects
     Qt3DInput::QMouseDevice *mMouseDevice = nullptr;