[3D] notify user if the 3D scene export failed

python/3d/auto_generated/qgs3dmapscene.sip.in

@@ -79,9 +79,10 @@ Given screen error (in pixels) and distance from camera (in 3D world coordinates
 estimates the error in world space. Takes into account camera's field of view and the screen (3D view) size.
 %End
 
-    void exportScene( const Qgs3DMapExportSettings &exportSettings );
+    bool exportScene( const Qgs3DMapExportSettings &exportSettings );
 %Docstring
 Exports the scene according to the scene export settings
+Returns ``False`` if the operation failed
 %End
 
 

python/PyQt6/3d/auto_generated/qgs3dmapscene.sip.in

@@ -79,9 +79,10 @@ Given screen error (in pixels) and distance from camera (in 3D world coordinates
 estimates the error in world space. Takes into account camera's field of view and the screen (3D view) size.
 %End
 
-    void exportScene( const Qgs3DMapExportSettings &exportSettings );
+    bool exportScene( const Qgs3DMapExportSettings &exportSettings );
 %Docstring
 Exports the scene according to the scene export settings
+Returns ``False`` if the operation failed
 %End
 
 

src/3d/qgs3dmapscene.cpp

@@ -1006,7 +1006,7 @@ void Qgs3DMapScene::onCameraNavigationModeChanged()
   mCameraController->setCameraNavigationMode( mMap.cameraNavigationMode() );
 }
 
-void Qgs3DMapScene::exportScene( const Qgs3DMapExportSettings &exportSettings )
+bool Qgs3DMapScene::exportScene( const Qgs3DMapExportSettings &exportSettings )
 {
   QVector<QString> notParsedLayers;
   Qgs3DSceneExporter exporter;
@@ -1045,7 +1045,11 @@ void Qgs3DMapScene::exportScene( const Qgs3DMapExportSettings &exportSettings )
   if ( mTerrain )
     exporter.parseTerrain( mTerrain, "Terrain" );
 
-  exporter.save( exportSettings.sceneName(), exportSettings.sceneFolderPath() );
+  const bool sceneSaved = exporter.save( exportSettings.sceneName(), exportSettings.sceneFolderPath() );
+  if ( !sceneSaved )
+  {
+    return false;
+  }
 
   if ( !notParsedLayers.empty() )
   {
@@ -1054,6 +1058,8 @@ void Qgs3DMapScene::exportScene( const Qgs3DMapExportSettings &exportSettings )
       message += layerName + "\n";
     QgsMessageOutput::showMessage( tr( "3D exporter warning" ), message, QgsMessageOutput::MessageText );
   }
+
+  return true;
 }
 
 QVector<const QgsChunkNode *> Qgs3DMapScene::getLayerActiveChunkNodes( QgsMapLayer *layer )

src/3d/qgs3dmapscene.h

@@ -127,8 +127,11 @@ class _3D_EXPORT Qgs3DMapScene : public QObject
      */
     float worldSpaceError( float epsilon, float distance ) const;
 
-    //! Exports the scene according to the scene export settings
-    void exportScene( const Qgs3DMapExportSettings &exportSettings );
+    /**
+     * Exports the scene according to the scene export settings
+     * Returns FALSE if the operation failed
+     */
+    bool exportScene( const Qgs3DMapExportSettings &exportSettings );
 
     /**
      * Returns the active chunk nodes of \a layer

src/3d/qgs3dsceneexporter.cpp

@@ -808,22 +808,27 @@ Qgs3DExportObject *Qgs3DSceneExporter::processPoints( Qt3DCore::QEntity *entity,
   return obj;
 }
 
-void Qgs3DSceneExporter::save( const QString &sceneName, const QString &sceneFolderPath, int precision )
+bool Qgs3DSceneExporter::save( const QString &sceneName, const QString &sceneFolderPath, int precision )
 {
+  if ( mObjects.isEmpty() )
+  {
+    return false;
+  }
+
   const QString objFilePath = QDir( sceneFolderPath ).filePath( sceneName + QStringLiteral( ".obj" ) );
   const QString mtlFilePath = QDir( sceneFolderPath ).filePath( sceneName + QStringLiteral( ".mtl" ) );
 
   QFile file( objFilePath );
   if ( !file.open( QIODevice::WriteOnly | QIODevice::Text | QIODevice::Truncate ) )
   {
     QgsDebugError( QStringLiteral( "Scene can not be exported to '%1'. File access error." ).arg( objFilePath ) );
-    return;
+    return false;
   }
   QFile mtlFile( mtlFilePath );
   if ( !mtlFile.open( QIODevice::WriteOnly | QIODevice::Text | QIODevice::Truncate ) )
   {
     QgsDebugError( QStringLiteral( "Scene can not be exported to '%1'. File access error." ).arg( mtlFilePath ) );
-    return;
+    return false;
   }
 
   float maxfloat = std::numeric_limits<float>::max(), minFloat = std::numeric_limits<float>::lowest();
@@ -863,6 +868,7 @@ void Qgs3DSceneExporter::save( const QString &sceneName, const QString &sceneFol
   }
 
   QgsDebugMsgLevel( QStringLiteral( "Scene exported to '%1'" ).arg( objFilePath ), 2 );
+  return true;
 }
 
 QString Qgs3DSceneExporter::getObjectName( const QString &name )

src/3d/qgs3dsceneexporter.h

@@ -76,8 +76,11 @@ class _3D_EXPORT Qgs3DSceneExporter : public Qt3DCore::QEntity
     //! Creates terrain export objects from the terrain entity
     void parseTerrain( QgsTerrainEntity *terrain, const QString &layer );
 
-    //! Saves the scene to a .obj file
-    void save( const QString &sceneName, const QString &sceneFolderPath, int precision = 6 );
+    /**
+     * Saves the scene to a .obj file
+     * Returns FALSE if the operation failed
+     */
+    bool save( const QString &sceneName, const QString &sceneFolderPath, int precision = 6 );
 
     //! Sets whether the triangles will look smooth
     void setSmoothEdges( bool smoothEdges ) { mSmoothEdges = smoothEdges; }

src/app/3d/qgs3dmapcanvaswidget.cpp

@@ -556,7 +556,7 @@ void Qgs3DMapCanvasWidget::exportScene()
   QgsGui::enableAutoGeometryRestore( &dlg );
 
   Qgs3DMapExportSettings exportSettings;
-  QgsMap3DExportWidget w( mCanvas->scene(), &exportSettings );
+  QgsMap3DExportWidget exportWidget( mCanvas->scene(), &exportSettings );
 
   QDialogButtonBox *buttons = new QDialogButtonBox( QDialogButtonBox::Cancel | QDialogButtonBox::Help | QDialogButtonBox::Ok, &dlg );
 
@@ -565,10 +565,21 @@ void Qgs3DMapCanvasWidget::exportScene()
   connect( buttons, &QDialogButtonBox::helpRequested, &dlg, [=] { QgsHelp::openHelp( QStringLiteral( "map_views/3d_map_view.html" ) ); } );
 
   QVBoxLayout *layout = new QVBoxLayout( &dlg );
-  layout->addWidget( &w, 1 );
+  layout->addWidget( &exportWidget, 1 );
   layout->addWidget( buttons );
   if ( dlg.exec() )
-    w.exportScene();
+  {
+    const bool success = exportWidget.exportScene();
+    const QString exportFilePath = QDir( exportSettings.sceneFolderPath() ).filePath( exportSettings.sceneName() + QStringLiteral( ".obj" ) );
+    if ( success )
+    {
+      mMessageBar->pushMessage( tr( "Export 3D scene" ), tr( "Successfully exported scene to <a href=\"%1\">%2</a>" ).arg( QUrl::fromLocalFile( exportFilePath ).toString(), QDir::toNativeSeparators( exportFilePath ) ), Qgis::MessageLevel::Success, 0 );
+    }
+    else
+    {
+      mMessageBar->pushMessage( tr( "Export 3D scene" ), tr( "Unable to export scene to <a href=\"%1\">%2</a>" ).arg( QUrl::fromLocalFile( exportFilePath ).toString(), QDir::toNativeSeparators( exportFilePath ) ), Qgis::MessageLevel::Warning, 0 );
+    }
+  }
 }
 
 void Qgs3DMapCanvasWidget::onMainCanvasLayersChanged()

src/app/3d/qgsmap3dexportwidget.cpp

@@ -80,7 +80,7 @@ void QgsMap3DExportWidget::settingsChanged()
   mExportSettings->setScale( ui->scaleSpinBox->value() );
 }
 
-void QgsMap3DExportWidget::exportScene()
+bool QgsMap3DExportWidget::exportScene()
 {
-  mScene->exportScene( *mExportSettings );
+  return mScene->exportScene( *mExportSettings );
 }

src/app/3d/qgsmap3dexportwidget.h

@@ -35,7 +35,7 @@ class QgsMap3DExportWidget : public QWidget
     ~QgsMap3DExportWidget();
 
     void loadSettings();
-    void exportScene();
+    bool exportScene();
   private slots:
     void settingsChanged();
 

tests/src/3d/testqgs3drendering.cpp

@@ -2274,7 +2274,8 @@ void TestQgs3DRendering::do3DSceneExport( const QString &testName, int zoomLevel
     exporter.parseTerrain( terrainEntity, "DEM_Tile" );
 
   QString objFileName = QString( "%1-%2" ).arg( testName ).arg( zoomLevelsCount );
-  exporter.save( objFileName, QDir::tempPath(), 3 );
+  const bool saved = exporter.save( objFileName, QDir::tempPath(), 3 );
+  QVERIFY( saved );
 
   int sum = 0;
   for ( auto o : qAsConst( exporter.mObjects ) )