Fix issues with camera view center adjustments + option to show the center

Author: wonder-sk

src/3d/qgs3dmapscene.cpp

@@ -23,6 +23,7 @@
 #include <Qt3DExtras/QForwardRenderer>
 #include <Qt3DExtras/QPhongMaterial>
 #include <Qt3DExtras/QSkyboxEntity>
+#include <Qt3DExtras/QSphereMesh>
 #include <Qt3DLogic/QFrameAction>
 
 #include <QTimer>
@@ -34,7 +35,6 @@
 #include "qgscameracontroller.h"
 #include "qgschunkedentity_p.h"
 #include "qgschunknode_p.h"
-#include "qgsraycastingutils_p.h"
 #include "qgsterrainentity_p.h"
 #include "qgsterraingenerator.h"
 #include "qgsvectorlayer.h"
@@ -74,6 +74,8 @@ Qgs3DMapScene::Qgs3DMapScene( const Qgs3DMapSettings &map, Qt3DExtras::QForwardR
   mCameraController->setCamera( camera );
   mCameraController->resetView( 1000 );
 
+  addCameraViewCenterEntity( camera );
+
   // create terrain entity
 
   createTerrain();
@@ -255,21 +257,6 @@ void Qgs3DMapScene::onCameraChanged()
     camera->setFarPlane( ffar * 2 );
     camera->setNearPlane( fnear / 2 );
 
-    // figure out our distance from terrain and update the camera's view center
-    // so that camera tilting and rotation is around a point on terrain, not an point at fixed elevation
-    QVector3D intersectionPoint;
-    QgsRayCastingUtils::Ray3D ray = QgsRayCastingUtils::rayForViewportAndCamera(
-                                      mCameraController->viewport().size(),
-                                      mCameraController->viewport().center(),
-                                      QRectF( 0.0, 0.0, 1.0, 1.0 ),
-                                      mCameraController->camera() );
-    if ( mTerrain->rayIntersection( ray, intersectionPoint ) )
-    {
-      float dist = ( intersectionPoint - mCameraController->camera()->position() ).length();
-      mCameraController->blockSignals( true );
-      mCameraController->setLookingAtPoint( QgsVector3D( intersectionPoint.x(), intersectionPoint.y(), intersectionPoint.z() ), dist );
-      mCameraController->blockSignals( false );
-    }
   }
   else
     qDebug() << "no terrain - not setting near/far plane";
@@ -321,7 +308,7 @@ void Qgs3DMapScene::createTerrainDeferred()
   if ( mMap.showTerrainBoundingBoxes() )
     mTerrain->setShowBoundingBoxes( true );
 
-  mCameraController->addTerrainPicker( mTerrain->terrainPicker() );
+  mCameraController->setTerrainEntity( mTerrain );
 
   mChunkEntities << mTerrain;
 
@@ -435,3 +422,31 @@ void Qgs3DMapScene::removeLayerEntity( QgsMapLayer *layer )
     disconnect( vlayer, &QgsVectorLayer::selectionChanged, this, &Qgs3DMapScene::onLayerRenderer3DChanged );
   }
 }
+
+void Qgs3DMapScene::addCameraViewCenterEntity( Qt3DRender::QCamera *camera )
+{
+  mEntityCameraViewCenter = new Qt3DCore::QEntity;
+
+  Qt3DCore::QTransform *trCameraViewCenter = new Qt3DCore::QTransform;
+  mEntityCameraViewCenter->addComponent( trCameraViewCenter );
+  connect( camera, &Qt3DRender::QCamera::viewCenterChanged, this, [trCameraViewCenter, camera]
+  {
+    trCameraViewCenter->setTranslation( camera->viewCenter() );
+  } );
+
+  Qt3DExtras::QPhongMaterial *materialCameraViewCenter = new Qt3DExtras::QPhongMaterial;
+  materialCameraViewCenter->setAmbient( Qt::red );
+  mEntityCameraViewCenter->addComponent( materialCameraViewCenter );
+
+  Qt3DExtras::QSphereMesh *rendererCameraViewCenter = new Qt3DExtras::QSphereMesh;
+  rendererCameraViewCenter->setRadius( 10 );
+  mEntityCameraViewCenter->addComponent( rendererCameraViewCenter );
+
+  mEntityCameraViewCenter->setEnabled( mMap.showCameraViewCenter() );
+  mEntityCameraViewCenter->setParent( this );
+
+  connect( &mMap, &Qgs3DMapSettings::showCameraViewCenterChanged, this, [this]
+  {
+    mEntityCameraViewCenter->setEnabled( mMap.showCameraViewCenter() );
+  } );
+}

src/3d/qgs3dmapscene.h

@@ -83,6 +83,7 @@ class _3D_EXPORT Qgs3DMapScene : public Qt3DCore::QEntity
   private:
     void addLayerEntity( QgsMapLayer *layer );
     void removeLayerEntity( QgsMapLayer *layer );
+    void addCameraViewCenterEntity( Qt3DRender::QCamera *camera );
 
   private:
     const Qgs3DMapSettings &mMap;
@@ -93,6 +94,8 @@ class _3D_EXPORT Qgs3DMapScene : public Qt3DCore::QEntity
     //! Forward renderer provided by 3D window
     Qt3DExtras::QForwardRenderer *mForwardRenderer = nullptr;
     QList<QgsChunkedEntity *> mChunkEntities;
+    //! Entity that shows view center - useful for debugging camera issues
+    Qt3DCore::QEntity *mEntityCameraViewCenter = nullptr;
     //! Keeps track of entities that belong to a particular layer
     QMap<QgsMapLayer *, Qt3DCore::QEntity *> mLayerEntities;
     bool mTerrainUpdateScheduled = false;

src/3d/qgs3dmapsettings.cpp

@@ -38,6 +38,7 @@ Qgs3DMapSettings::Qgs3DMapSettings( const Qgs3DMapSettings &other )
   , mMaxTerrainGroundError( other.mMaxTerrainGroundError )
   , mShowTerrainBoundingBoxes( other.mShowTerrainBoundingBoxes )
   , mShowTerrainTileInfo( other.mShowTerrainTileInfo )
+  , mShowCameraViewCenter( other.mShowCameraViewCenter )
   , mLayers( other.mLayers )
   , mSkyboxEnabled( other.mSkyboxEnabled )
   , mSkyboxFileBase( other.mSkyboxFileBase )
@@ -133,6 +134,7 @@ void Qgs3DMapSettings::readXml( const QDomElement &elem, const QgsReadWriteConte
   QDomElement elemDebug = elem.firstChildElement( "debug" );
   mShowTerrainBoundingBoxes = elemDebug.attribute( "bounding-boxes", "0" ).toInt();
   mShowTerrainTileInfo = elemDebug.attribute( "terrain-tile-info", "0" ).toInt();
+  mShowCameraViewCenter = elemDebug.attribute( "camera-view-center", "0" ).toInt();
 }
 
 QDomElement Qgs3DMapSettings::writeXml( QDomDocument &doc, const QgsReadWriteContext &context ) const
@@ -189,6 +191,7 @@ QDomElement Qgs3DMapSettings::writeXml( QDomDocument &doc, const QgsReadWriteCon
   QDomElement elemDebug = doc.createElement( "debug" );
   elemDebug.setAttribute( "bounding-boxes", mShowTerrainBoundingBoxes ? 1 : 0 );
   elemDebug.setAttribute( "terrain-tile-info", mShowTerrainTileInfo ? 1 : 0 );
+  elemDebug.setAttribute( "camera-view-center", mShowCameraViewCenter ? 1 : 0 );
   elem.appendChild( elemDebug );
 
   return elem;
@@ -377,6 +380,15 @@ void Qgs3DMapSettings::setShowTerrainTilesInfo( bool enabled )
   emit showTerrainTilesInfoChanged();
 }
 
+void Qgs3DMapSettings::setShowCameraViewCenter( bool enabled )
+{
+  if ( mShowCameraViewCenter == enabled )
+    return;
+
+  mShowCameraViewCenter = enabled;
+  emit showCameraViewCenterChanged();
+}
+
 void Qgs3DMapSettings::setShowLabels( bool enabled )
 {
   if ( mShowLabels == enabled )

src/3d/qgs3dmapsettings.h

@@ -227,6 +227,18 @@ class _3D_EXPORT Qgs3DMapSettings : public QObject
     void setShowTerrainTilesInfo( bool enabled );
     //! Returns whether to display extra tile info on top of terrain tiles (for debugging)
     bool showTerrainTilesInfo() const { return mShowTerrainTileInfo; }
+
+    /**
+     * Sets whether to show camera's view center as a sphere (for debugging)
+     * \since QGIS 3.4
+     */
+    void setShowCameraViewCenter( bool enabled );
+
+    /**
+     * Returns whether to show camera's view center as a sphere (for debugging)
+     * \since QGIS 3.4
+     */
+    bool showCameraViewCenter() const { return mShowCameraViewCenter; }
     //! Sets whether to display labels on terrain tiles
     void setShowLabels( bool enabled );
     //! Returns whether to display labels on terrain tiles
@@ -253,6 +265,12 @@ class _3D_EXPORT Qgs3DMapSettings : public QObject
     void showTerrainBoundingBoxesChanged();
     //! Emitted when the flag whether terrain's tile info is shown has changed
     void showTerrainTilesInfoChanged();
+
+    /**
+     * Emitted when the flag whether camera's view center is shown has changed
+     * \since QGIS 3.4
+     */
+    void showCameraViewCenterChanged();
     //! Emitted when the flag whether labels are displayed on terrain tiles has changed
     void showLabelsChanged();
 
@@ -269,6 +287,7 @@ class _3D_EXPORT Qgs3DMapSettings : public QObject
     float mMaxTerrainGroundError = 1.f;  //!< Maximum allowed horizontal map error in map units (determines how many zoom levels will be used)
     bool mShowTerrainBoundingBoxes = false;  //!< Whether to show bounding boxes of entities - useful for debugging
     bool mShowTerrainTileInfo = false;  //!< Whether to draw extra information about terrain tiles to the textures - useful for debugging
+    bool mShowCameraViewCenter = false;  //!< Whether to show camera view center as a sphere - useful for debugging
     bool mShowLabels = false; //!< Whether to display labels on terrain tiles
     QList<QgsMapLayerRef> mLayers;   //!< Layers to be rendered
     QList<QgsAbstract3DRenderer *> mRenderers;  //!< Extra stuff to render as 3D object

src/3d/qgscameracontroller.cpp

@@ -14,6 +14,8 @@
  ***************************************************************************/
 
 #include "qgscameracontroller.h"
+#include "qgsraycastingutils_p.h"
+#include "qgsterrainentity_p.h"
 #include "qgsvector3d.h"
 
 #include "qgis.h"
@@ -129,10 +131,12 @@ QgsCameraController::QgsCameraController( Qt3DCore::QNode *parent )
   addComponent( mLogicalDevice );
 }
 
-void QgsCameraController::addTerrainPicker( Qt3DRender::QObjectPicker *picker )
+void QgsCameraController::setTerrainEntity( QgsTerrainEntity *te )
 {
+  mTerrainEntity = te;
+
   // object picker for terrain for correct map panning
-  connect( picker, &Qt3DRender::QObjectPicker::pressed, this, &QgsCameraController::onPickerMousePressed );
+  connect( te->terrainPicker(), &Qt3DRender::QObjectPicker::pressed, this, &QgsCameraController::onPickerMousePressed );
 }
 
 void QgsCameraController::setCamera( Qt3DRender::QCamera *camera )
@@ -295,6 +299,25 @@ void QgsCameraController::frameTriggered( float dt )
   if ( mCameraData != oldCamData )
   {
     mCameraData.setCamera( mCamera );
+
+    bool viewCenterChanged = ( mCameraData.x != oldCamData.x || mCameraData.y != oldCamData.y || mCameraData.elev != oldCamData.elev );
+    if ( mTerrainEntity && viewCenterChanged )
+    {
+      // figure out our distance from terrain and update the camera's view center
+      // so that camera tilting and rotation is around a point on terrain, not an point at fixed elevation
+      QVector3D intersectionPoint;
+      QgsRayCastingUtils::Ray3D ray = QgsRayCastingUtils::rayForViewportAndCamera( mViewport.size(), QPointF( mViewport.width() / 2., mViewport.height() / 2. ), QRectF( 0.0, 0.0, 1.0, 1.0 ), mCamera );
+      if ( mTerrainEntity->rayIntersection( ray, intersectionPoint ) )
+      {
+        float dist = ( intersectionPoint - mCamera->position() ).length();
+        mCameraData.dist = dist;
+        mCameraData.x = intersectionPoint.x();
+        mCameraData.y = intersectionPoint.z();
+        mCameraData.elev = intersectionPoint.y();
+        mCameraData.setCamera( mCamera );
+      }
+    }
+
     emit cameraChanged();
   }
 }

src/3d/qgscameracontroller.h

@@ -25,6 +25,7 @@
 class QDomDocument;
 class QDomElement;
 
+class QgsTerrainEntity;
 class QgsVector3D;
 
 /**
@@ -48,9 +49,11 @@ class _3D_EXPORT QgsCameraController : public Qt3DCore::QEntity
 
     /**
      * Connects to object picker attached to terrain entity. Called internally from 3D scene.
-     * This allows camera controller understand how far from the camera is the terrain under mouse cursor
+     * This allows camera controller understand how far from the camera is the terrain under mouse cursor.
+     * Also it allows adjustment of camera's view center to a point on terrain.
      */
-    void addTerrainPicker( Qt3DRender::QObjectPicker *picker );
+    void setTerrainEntity( QgsTerrainEntity *te );
+
     //! Assigns camera that should be controlled by this class. Called internally from 3D scene.
     void setCamera( Qt3DRender::QCamera *camera );
     //! Sets viewport rectangle. Called internally from 3D canvas. Allows conversion of mouse coordinates.
@@ -95,6 +98,8 @@ class _3D_EXPORT QgsCameraController : public Qt3DCore::QEntity
     //! height of terrain when mouse button was last pressed - for camera control
     float mLastPressedHeight = 0;
 
+    QPointer<QgsTerrainEntity> mTerrainEntity;
+
     struct CameraData
     {
       float x = 0, y = 0, elev = 0;  // ground point towards which the camera is looking

src/3d/qgsraycastingutils_p.cpp

@@ -302,7 +302,7 @@ static QRect windowViewport( const QSize &area, const QRectF &relativeViewport )
   return relativeViewport.toRect();
 }
 
-static QgsRayCastingUtils::Ray3D intersectionRay( const QPoint &pos, const QMatrix4x4 &viewMatrix,
+static QgsRayCastingUtils::Ray3D intersectionRay( const QPointF &pos, const QMatrix4x4 &viewMatrix,
     const QMatrix4x4 &projectionMatrix, const QRect &viewport )
 {
   QVector3D nearPos = QVector3D( pos.x(), pos.y(), 0.0f );
@@ -320,7 +320,7 @@ namespace QgsRayCastingUtils
 {
 
   Ray3D rayForViewportAndCamera( const QSize &area,
-                                 const QPoint &pos,
+                                 const QPointF &pos,
                                  const QRectF &relativeViewport,
                                  const Qt3DRender::QCamera *camera )
   {
@@ -330,7 +330,7 @@ namespace QgsRayCastingUtils
     const QRect viewport = windowViewport( area, relativeViewport );
 
     // In GL the y is inverted compared to Qt
-    const QPoint glCorrectPos = QPoint( pos.x(), area.isValid() ? area.height() - pos.y() : pos.y() );
+    const QPointF glCorrectPos = QPointF( pos.x(), area.isValid() ? area.height() - pos.y() : pos.y() );
     const auto ray = intersectionRay( glCorrectPos, viewMatrix, projectionMatrix, viewport );
     return ray;
   }

src/3d/qgsraycastingutils_p.h

@@ -109,7 +109,7 @@ namespace QgsRayCastingUtils
    * \since QGIS 3.4
    */
   Ray3D rayForViewportAndCamera( const QSize &area,
-                                 const QPoint &pos,
+                                 const QPointF &pos,
                                  const QRectF &relativeViewport,
                                  const Qt3DRender::QCamera *camera );
 }

src/app/3d/qgs3dmapconfigwidget.cpp

@@ -60,6 +60,7 @@ Qgs3DMapConfigWidget::Qgs3DMapConfigWidget( Qgs3DMapSettings *map, QgsMapCanvas
   chkShowLabels->setChecked( mMap->showLabels() );
   chkShowTileInfo->setChecked( mMap->showTerrainTilesInfo() );
   chkShowBoundingBoxes->setChecked( mMap->showTerrainBoundingBoxes() );
+  chkShowCameraViewCenter->setChecked( mMap->showCameraViewCenter() );
 
   connect( cboTerrainLayer, static_cast<void ( QComboBox::* )( int )>( &QgsMapLayerComboBox::currentIndexChanged ), this, &Qgs3DMapConfigWidget::onTerrainLayerChanged );
   connect( spinMapResolution, static_cast<void ( QSpinBox::* )( int )>( &QSpinBox::valueChanged ), this, &Qgs3DMapConfigWidget::updateMaxZoomLevel );
@@ -125,6 +126,7 @@ void Qgs3DMapConfigWidget::apply()
   mMap->setShowLabels( chkShowLabels->isChecked() );
   mMap->setShowTerrainTilesInfo( chkShowTileInfo->isChecked() );
   mMap->setShowTerrainBoundingBoxes( chkShowBoundingBoxes->isChecked() );
+  mMap->setShowCameraViewCenter( chkShowCameraViewCenter->isChecked() );
 }
 
 void Qgs3DMapConfigWidget::onTerrainLayerChanged()

src/ui/3d/map3dconfigwidget.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>691</width>
-    <height>775</height>
+    <height>830</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -186,6 +186,13 @@
      </property>
     </widget>
    </item>
+   <item>
+    <widget class="QCheckBox" name="chkShowCameraViewCenter">
+     <property name="text">
+      <string>Show camera's view center</string>
+     </property>
+    </widget>
+   </item>
    <item>
     <spacer name="verticalSpacer">
      <property name="orientation">