[Virtual Point Clouds] Add combobox to adjust the switching between rendering overview only and sub index rendering

python/3d/auto_generated/qgspointcloudlayer3drenderer.sip.in

@@ -119,6 +119,24 @@ Sets the renderer behavior when zoomed out
 Returns the renderer behavior when zoomed out
 
 .. versionadded:: 3.42
+%End
+
+    void setOverviewSwitchingScale( double scale );
+%Docstring
+Sets the overview switching scale
+
+Used to determine when point clouds switch from rendering bounding boxes
+to displaying full point data. The value is compared against screen
+space error (SSE) calculated from camera distance and node size.
+
+.. versionadded:: 4.0
+%End
+
+    double overviewSwitchingScale() const;
+%Docstring
+Returns the overview switching scale
+
+.. versionadded:: 4.0
 %End
 
   private:

python/PyQt6/3d/auto_generated/qgspointcloudlayer3drenderer.sip.in

@@ -119,6 +119,24 @@ Sets the renderer behavior when zoomed out
 Returns the renderer behavior when zoomed out
 
 .. versionadded:: 3.42
+%End
+
+    void setOverviewSwitchingScale( double scale );
+%Docstring
+Sets the overview switching scale
+
+Used to determine when point clouds switch from rendering bounding boxes
+to displaying full point data. The value is compared against screen
+space error (SSE) calculated from camera distance and node size.
+
+.. versionadded:: 4.0
+%End
+
+    double overviewSwitchingScale() const;
+%Docstring
+Returns the overview switching scale
+
+.. versionadded:: 4.0
 %End
 
   private:

python/PyQt6/core/auto_generated/pointcloud/qgspointcloudrenderer.sip.in

@@ -623,6 +623,26 @@ Sets the renderer behavior when zoomed out
 Returns the renderer behavior when zoomed out
 
 .. versionadded:: 3.42
+%End
+
+    void setOverviewSwitchingScale( const double value );
+%Docstring
+Sets the overview switching scale
+
+Point clouds whose extents intersect the map extent are considered
+visible. When zoomed out beyond the overview switching scale (render
+extent exceeds average point cloud dimensions by the scale factor), and
+overview zoom-out behavior is enabled, the overview is rendered instead
+of an individual point cloud.
+
+.. versionadded:: 4.0
+%End
+
+    double overviewSwitchingScale() const;
+%Docstring
+Returns the overview switching scale
+
+.. versionadded:: 4.0
 %End
 
   protected:

python/core/auto_generated/pointcloud/qgspointcloudrenderer.sip.in

@@ -623,6 +623,26 @@ Sets the renderer behavior when zoomed out
 Returns the renderer behavior when zoomed out
 
 .. versionadded:: 3.42
+%End
+
+    void setOverviewSwitchingScale( const double value );
+%Docstring
+Sets the overview switching scale
+
+Point clouds whose extents intersect the map extent are considered
+visible. When zoomed out beyond the overview switching scale (render
+extent exceeds average point cloud dimensions by the scale factor), and
+overview zoom-out behavior is enabled, the overview is rendered instead
+of an individual point cloud.
+
+.. versionadded:: 4.0
+%End
+
+    double overviewSwitchingScale() const;
+%Docstring
+Returns the overview switching scale
+
+.. versionadded:: 4.0
 %End
 
   protected:

src/3d/qgspointcloudlayer3drenderer.cpp

@@ -147,6 +147,7 @@ QgsPointCloudLayer3DRenderer *QgsPointCloudLayer3DRenderer::clone() const
   r->setMaximumScreenError( mMaximumScreenError );
   r->setShowBoundingBoxes( mShowBoundingBoxes );
   r->setZoomOutBehavior( mZoomOutBehavior );
+  r->setOverviewSwitchingScale( mOverviewSwitchingScale );
   return r;
 }
 
@@ -188,6 +189,7 @@ void QgsPointCloudLayer3DRenderer::writeXml( QDomElement &elem, const QgsReadWri
   elem.setAttribute( u"show-bounding-boxes"_s, showBoundingBoxes() ? u"1"_s : u"0"_s );
   elem.setAttribute( u"point-budget"_s, mPointBudget );
   elem.setAttribute( u"zoom-out-behavior"_s, qgsEnumValueToKey( mZoomOutBehavior ) );
+  elem.setAttribute( u"overview-switching-scale"_s, mOverviewSwitchingScale );
 
   QDomElement elemSymbol = doc.createElement( u"symbol"_s );
   if ( mSymbol )
@@ -209,6 +211,7 @@ void QgsPointCloudLayer3DRenderer::readXml( const QDomElement &elem, const QgsRe
   mMaximumScreenError = elem.attribute( u"max-screen-error"_s, u"3.0"_s ).toDouble();
   mPointBudget = elem.attribute( u"point-budget"_s, u"5000000"_s ).toInt();
   mZoomOutBehavior = qgsEnumKeyToValue( elem.attribute( u"zoom-out-behavior"_s ), Qgis::PointCloudZoomOutRenderBehavior::RenderExtents );
+  mOverviewSwitchingScale = elem.attribute( u"overview-switching-scale"_s, u"1.0"_s ).toDouble();
 
   if ( symbolType == "single-color"_L1 )
     mSymbol = std::make_unique<QgsSingleColorPointCloud3DSymbol>();

src/3d/qgspointcloudlayer3drenderer.h

@@ -315,13 +315,31 @@ class _3D_EXPORT QgsPointCloudLayer3DRenderer : public QgsAbstractPointCloud3DRe
       */
     Qgis::PointCloudZoomOutRenderBehavior zoomOutBehavior() const { return mZoomOutBehavior; }
 
+    /**
+      * Sets the overview switching scale
+      *
+      * Used to determine when point clouds
+      * switch from rendering bounding boxes to displaying full point data.
+      * The value is compared against screen space error (SSE) calculated from
+      * camera distance and node size.
+      * \since QGIS 4.0
+      */
+    void setOverviewSwitchingScale( double scale ) { mOverviewSwitchingScale = scale; }
+
+    /**
+      * Returns the overview switching scale
+      * \since QGIS 4.0
+      */
+    double overviewSwitchingScale() const { return mOverviewSwitchingScale; }
+
   private:
     QgsMapLayerRef mLayerRef; //!< Layer used to extract mesh data from
     std::unique_ptr<QgsPointCloud3DSymbol> mSymbol;
     double mMaximumScreenError = 3.0;
     bool mShowBoundingBoxes = false;
     int mPointBudget = 5000000;
     Qgis::PointCloudZoomOutRenderBehavior mZoomOutBehavior = Qgis::PointCloudZoomOutRenderBehavior::RenderExtents;
+    double mOverviewSwitchingScale = 1.0;
 
   private:
 #ifdef SIP_RUN

src/3d/qgsvirtualpointcloudentity_p.cpp

@@ -139,6 +139,11 @@ void QgsVirtualPointCloudEntity::handleSceneUpdate( const SceneContext &sceneCon
 {
   QgsVector3D cameraPosMapCoords = QgsVector3D( sceneContext.cameraPos ) + mapSettings()->origin();
   const QVector<QgsPointCloudSubIndex> subIndexes = provider()->subIndexes();
+
+  const QgsPointCloudLayer3DRenderer *rendererBehavior = dynamic_cast<QgsPointCloudLayer3DRenderer *>( mLayer->renderer3D() );
+  const double overviewSwitchingScale = rendererBehavior ? rendererBehavior->overviewSwitchingScale() : 1;
+  qsizetype subIndexesRendered = 0;
+
   for ( int i = 0; i < subIndexes.size(); ++i )
   {
     // If the chunked entity needs an update, do it even if it's occluded,
@@ -160,23 +165,30 @@ void QgsVirtualPointCloudEntity::handleSceneUpdate( const SceneContext &sceneCon
     const float epsilon = static_cast<float>( std::min( box3D.width(), box3D.height() ) ) / SPAN;
     const float distance = static_cast<float>( box3D.distanceTo( cameraPosMapCoords ) );
     const float sse = Qgs3DUtils::screenSpaceError( epsilon, distance, sceneContext.screenSizePx, sceneContext.cameraFov );
-    constexpr float THRESHOLD = .2;
+    const double THRESHOLD = 0.2 / overviewSwitchingScale;
 
     // always display as bbox for the initial temporary camera pos (0, 0, 0)
     // then once the camera changes we display as bbox depending on screen space error
-    const bool displayAsBbox = sceneContext.cameraPos.isNull() || sse < THRESHOLD;
-    if ( !displayAsBbox && !subIndexes.at( i ).index() )
-      emit subIndexNeedsLoading( i );
-
+    const bool displayAsBbox = sceneContext.cameraPos.isNull() || sse < static_cast<float>( THRESHOLD );
+    if ( !displayAsBbox )
+    {
+      subIndexesRendered += 1;
+      if ( !subIndexes.at( i ).index() )
+        emit subIndexNeedsLoading( i );
+    }
     setRenderSubIndexAsBbox( i, displayAsBbox );
     if ( !displayAsBbox && mChunkedEntitiesMap.contains( i ) )
       mChunkedEntitiesMap[i]->handleSceneUpdate( sceneContext );
   }
   updateBboxEntity();
 
-  const QgsPointCloudLayer3DRenderer *rendererBehavior = dynamic_cast<QgsPointCloudLayer3DRenderer *>( mLayer->renderer3D() );
   if ( provider()->overview() && rendererBehavior && ( rendererBehavior->zoomOutBehavior() == Qgis::PointCloudZoomOutRenderBehavior::RenderOverview || rendererBehavior->zoomOutBehavior() == Qgis::PointCloudZoomOutRenderBehavior::RenderOverviewAndExtents ) )
   {
+    // no need to render the overview if all sub indexes are shown
+    if ( !mChunkedEntitiesMap.isEmpty() && subIndexesRendered == mChunkedEntitiesMap.size() )
+      mOverviewEntity->setEnabled( false );
+    else
+      mOverviewEntity->setEnabled( true );
     mOverviewEntity->handleSceneUpdate( sceneContext );
   }
 }

src/app/3d/qgspointcloud3dsymbolwidget.cpp

@@ -152,14 +152,22 @@ QgsPointCloud3DSymbolWidget::QgsPointCloud3DSymbolWidget( QgsPointCloudLayer *la
       {
         mZoomOutOptions->addItem( tr( "Show Overview Only" ), QVariant::fromValue( Qgis::PointCloudZoomOutRenderBehavior::RenderOverview ) );
         mZoomOutOptions->addItem( tr( "Show Extents Over Overview" ), QVariant::fromValue( Qgis::PointCloudZoomOutRenderBehavior::RenderOverviewAndExtents ) );
+
+        for ( auto it = mOverviewSwitchingScaleMap.constBegin(); it != mOverviewSwitchingScaleMap.constEnd(); ++it )
+        {
+          mOverviewSwitchingScale->addItem( it.value(), it.key() );
+        }
+        setOverviewSwitchingScale( 1.0 );
       }
     }
     else
     {
       mZoomOutOptions->setEnabled( false );
+      mOverviewSwitchingScale->setEnabled( false );
     }
 
     connect( mZoomOutOptions, qOverload<int>( &QComboBox::currentIndexChanged ), this, &QgsPointCloud3DSymbolWidget::emitChangedSignal );
+    connect( mOverviewSwitchingScale, qOverload<int>( &QComboBox::currentIndexChanged ), this, &QgsPointCloud3DSymbolWidget::emitChangedSignal );
   }
   else
   {
@@ -700,6 +708,16 @@ Qgis::PointCloudZoomOutRenderBehavior QgsPointCloud3DSymbolWidget::zoomOutBehavi
   return mZoomOutOptions->currentData().value<Qgis::PointCloudZoomOutRenderBehavior>();
 }
 
+void QgsPointCloud3DSymbolWidget::setOverviewSwitchingScale( double scale )
+{
+  mOverviewSwitchingScale->setCurrentIndex( mOverviewSwitchingScale->findData( scale ) );
+}
+
+double QgsPointCloud3DSymbolWidget::overviewSwitchingScale() const
+{
+  return mOverviewSwitchingScaleMap.key( mOverviewSwitchingScale->currentText() );
+}
+
 void QgsPointCloud3DSymbolWidget::connectChildPanels( QgsPanelWidget *parent )
 {
   parent->connectChildPanel( mClassifiedRendererWidget );

src/app/3d/qgspointcloud3dsymbolwidget.h

@@ -49,6 +49,9 @@ class QgsPointCloud3DSymbolWidget : public QWidget, private Ui::QgsPointCloud3DS
     void setZoomOutBehavior( Qgis::PointCloudZoomOutRenderBehavior zoomOutBehavior );
     Qgis::PointCloudZoomOutRenderBehavior zoomOutBehavior() const;
 
+    void setOverviewSwitchingScale( double scale );
+    double overviewSwitchingScale() const;
+
     void connectChildPanels( QgsPanelWidget *parent );
 
   private slots:
@@ -77,6 +80,14 @@ class QgsPointCloud3DSymbolWidget : public QWidget, private Ui::QgsPointCloud3DS
     void setColorRampMinMax( double min, double max );
 
   private:
+    // for 2D rendering, see values in qgspointcloudrendererpropertieswidget.h
+    const QMap<double, QString> mOverviewSwitchingScaleMap {
+      { 5.0, "Much earlier" },
+      { 2.0, "Earlier" },
+      { 1.0, "Normal" },
+      { 0.5, "Later" }
+    };
+
     int mBlockChangedSignals = 0;
     int mDisableMinMaxWidgetRefresh = 0;
     QgsPointCloudClassifiedRendererWidget *mClassifiedRendererWidget = nullptr;

src/app/3d/qgspointcloudlayer3drendererwidget.cpp

@@ -65,6 +65,7 @@ QgsPointCloudLayer3DRenderer *QgsPointCloudLayer3DRendererWidget::renderer()
   renderer->setMaximumScreenError( mWidgetPointCloudSymbol->maximumScreenError() );
   renderer->setShowBoundingBoxes( mWidgetPointCloudSymbol->showBoundingBoxes() );
   renderer->setZoomOutBehavior( mWidgetPointCloudSymbol->zoomOutBehavior() );
+  renderer->setOverviewSwitchingScale( mWidgetPointCloudSymbol->overviewSwitchingScale() );
   return renderer;
 }
 

src/core/pointcloud/qgspointcloudlayer.cpp

@@ -987,9 +987,13 @@ void QgsPointCloudLayer::loadIndexesForRenderContext( QgsRenderContext &renderer
         if ( subIndex.at( i ).index() )
           continue;
 
+        const double overviewSwitchingScale = mRenderer ? mRenderer->overviewSwitchingScale() : 1.0;
+        const double widthThreshold = vpcProvider->averageSubIndexWidth()  * overviewSwitchingScale;
+        const double heightThreshold = vpcProvider->averageSubIndexHeight() * overviewSwitchingScale;
+
         if ( subIndex.at( i ).extent().intersects( renderExtent ) &&
-             ( renderExtent.width() < vpcProvider->averageSubIndexWidth() ||
-               renderExtent.height() < vpcProvider->averageSubIndexHeight() ) )
+             ( renderExtent.width() < widthThreshold ||
+               renderExtent.height() < heightThreshold ) )
         {
           mDataProvider->loadSubIndex( i );
         }

src/core/pointcloud/qgspointcloudlayerrenderer.cpp

@@ -216,8 +216,9 @@ bool QgsPointCloudLayerRenderer::render()
         visibleIndexes.append( si );
       }
     }
-    const bool zoomedOut = renderExtent.width() > mAverageSubIndexWidth ||
-                           renderExtent.height() > mAverageSubIndexHeight;
+    const double overviewSwitchingScale = mRenderer->overviewSwitchingScale();
+    const bool zoomedOut = renderExtent.width() > mAverageSubIndexWidth * overviewSwitchingScale ||
+                           renderExtent.height() > mAverageSubIndexHeight * overviewSwitchingScale;
     // if the overview of virtual point cloud exists, and we are zoomed out, we render just overview
     if ( mOverviewIndex && mOverviewIndex->isValid() && zoomedOut &&
          mRenderer->zoomOutBehavior() == Qgis::PointCloudZoomOutRenderBehavior::RenderOverview )

src/core/pointcloud/qgspointcloudrenderer.cpp

@@ -153,6 +153,11 @@ void QgsPointCloudRenderer::setMaximumScreenError( double error )
   mMaximumScreenError = error;
 }
 
+void QgsPointCloudRenderer::setOverviewSwitchingScale( double scale )
+{
+  mOverviewSwitchingScale = scale;
+}
+
 Qgis::RenderUnit QgsPointCloudRenderer::maximumScreenErrorUnit() const
 {
   return mMaximumScreenErrorUnit;
@@ -221,6 +226,7 @@ void QgsPointCloudRenderer::copyCommonProperties( QgsPointCloudRenderer *destina
   destination->setShowLabels( mShowLabels );
   destination->setLabelTextFormat( mLabelTextFormat );
   destination->setZoomOutBehavior( mZoomOutBehavior );
+  destination->setOverviewSwitchingScale( mOverviewSwitchingScale );
 }
 
 void QgsPointCloudRenderer::restoreCommonProperties( const QDomElement &element, const QgsReadWriteContext &context )
@@ -246,6 +252,7 @@ void QgsPointCloudRenderer::restoreCommonProperties( const QDomElement &element,
     mLabelTextFormat.readXml( element.firstChildElement( u"text-style"_s ), context );
   }
   mZoomOutBehavior = qgsEnumKeyToValue( element.attribute( u"zoomOutBehavior"_s ), Qgis::PointCloudZoomOutRenderBehavior::RenderExtents );
+  mOverviewSwitchingScale = element.attribute( u"overviewSwitchingScale"_s, u"1.0"_s ).toDouble();
 }
 
 void QgsPointCloudRenderer::saveCommonProperties( QDomElement &element, const QgsReadWriteContext &context ) const
@@ -272,7 +279,10 @@ void QgsPointCloudRenderer::saveCommonProperties( QDomElement &element, const Qg
     element.appendChild( mLabelTextFormat.writeXml( doc, context ) );
   }
   if ( mZoomOutBehavior != Qgis::PointCloudZoomOutRenderBehavior::RenderExtents )
+  {
     element.setAttribute( u"zoomOutBehavior"_s, qgsEnumValueToKey( mZoomOutBehavior ) );
+    element.setAttribute( u"overviewSwitchingScale"_s, qgsDoubleToString( mOverviewSwitchingScale ) );
+  }
 }
 
 Qgis::PointCloudSymbol QgsPointCloudRenderer::pointSymbol() const

src/core/pointcloud/qgspointcloudrenderer.h

@@ -712,6 +712,23 @@ class CORE_EXPORT QgsPointCloudRenderer
      */
     Qgis::PointCloudZoomOutRenderBehavior zoomOutBehavior() const { return mZoomOutBehavior; }
 
+    /**
+      * Sets the overview switching scale
+      *
+      * Point clouds whose extents intersect the map extent are considered visible.
+      * When zoomed out beyond the overview switching scale (render extent exceeds average
+      * point cloud dimensions by the scale factor), and overview zoom-out behavior is enabled,
+      * the overview is rendered instead of an individual point cloud.
+      * \since QGIS 4.0
+      */
+    void setOverviewSwitchingScale( const double value );
+
+    /**
+      * Returns the overview switching scale
+      * \since QGIS 4.0
+      */
+    double overviewSwitchingScale() const { return mOverviewSwitchingScale; }
+
   protected:
 
     /**
@@ -855,6 +872,7 @@ class CORE_EXPORT QgsPointCloudRenderer
     QgsTextFormat mLabelTextFormat;
 
     Qgis::PointCloudZoomOutRenderBehavior mZoomOutBehavior = Qgis::PointCloudZoomOutRenderBehavior::RenderExtents;
+    double mOverviewSwitchingScale = 1.0;
 };
 
 #endif // QGSPOINTCLOUDRENDERER_H