adjust screen space error from UI

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

@@ -62,6 +62,24 @@ Returns 3D symbol associated with the renderer
     virtual void resolveReferences( const QgsProject &project );
 
 
+    double maximumScreenError() const;
+%Docstring
+Returns the maximum screen error allowed when rendering the point cloud.
+
+Larger values result in a faster render with less points rendered.
+
+.. seealso:: :py:func:`setMaximumScreenError`
+%End
+
+    void setMaximumScreenError( double error );
+%Docstring
+Sets the maximum screen ``error`` allowed when rendering the point cloud.
+
+Larger values result in a faster render with less points rendered.
+
+.. seealso:: :py:func:`maximumScreenError`
+%End
+
   private:
     QgsPointCloudLayer3DRenderer( const QgsPointCloudLayer3DRenderer & );
     QgsPointCloudLayer3DRenderer &operator=( const QgsPointCloudLayer3DRenderer & );

src/3d/qgspointcloudlayer3drenderer.cpp

@@ -99,7 +99,7 @@ Qt3DCore::QEntity *QgsPointCloudLayer3DRenderer::createEntity( const Qgs3DMapSet
   if ( !mSymbol )
     return nullptr;
 
-  return new QgsPointCloudLayerChunkedEntity( pcl->dataProvider()->index(), map, dynamic_cast<QgsPointCloud3DSymbol *>( mSymbol->clone() ) );
+  return new QgsPointCloudLayerChunkedEntity( pcl->dataProvider()->index(), map, dynamic_cast<QgsPointCloud3DSymbol *>( mSymbol->clone() ), maximumScreenError() );
 }
 
 void QgsPointCloudLayer3DRenderer::setSymbol( QgsPointCloud3DSymbol *symbol )
@@ -148,3 +148,13 @@ void QgsPointCloudLayer3DRenderer::resolveReferences( const QgsProject &project
 {
   mLayerRef.setLayer( project.mapLayer( mLayerRef.layerId ) );
 }
+
+double QgsPointCloudLayer3DRenderer::maximumScreenError() const
+{
+  return mMaximumScreenError;
+}
+
+void QgsPointCloudLayer3DRenderer::setMaximumScreenError( double error )
+{
+  mMaximumScreenError = error;
+}

src/3d/qgspointcloudlayer3drenderer.h

@@ -178,9 +178,28 @@ class _3D_EXPORT QgsPointCloudLayer3DRenderer : public QgsAbstract3DRenderer
     void readXml( const QDomElement &elem, const QgsReadWriteContext &context ) override;
     void resolveReferences( const QgsProject &project ) override;
 
+    /**
+     * Returns the maximum screen error allowed when rendering the point cloud.
+     *
+     * Larger values result in a faster render with less points rendered.
+     *
+     * \see setMaximumScreenError()
+     */
+    double maximumScreenError() const;
+
+    /**
+     * Sets the maximum screen \a error allowed when rendering the point cloud.
+     *
+     * Larger values result in a faster render with less points rendered.
+     *
+     * \see maximumScreenError()
+     */
+    void setMaximumScreenError( double error );
+
   private:
     QgsMapLayerRef mLayerRef; //!< Layer used to extract mesh data from
     std::unique_ptr< QgsPointCloud3DSymbol > mSymbol;
+    double mMaximumScreenError = 1.0;
 
   private:
 #ifdef SIP_RUN

src/3d/qgspointcloudlayerchunkloader_p.cpp

@@ -190,8 +190,8 @@ QgsAABB nodeBoundsToAABB( QgsPointCloudDataBounds nodeBounds, QgsVector3D offset
 }
 
 
-QgsPointCloudLayerChunkedEntity::QgsPointCloudLayerChunkedEntity( QgsPointCloudIndex *pc, const Qgs3DMapSettings &map, QgsPointCloud3DSymbol *symbol )
-  : QgsChunkedEntity( 5, // max. allowed screen error (in pixels)  -- // TODO
+QgsPointCloudLayerChunkedEntity::QgsPointCloudLayerChunkedEntity( QgsPointCloudIndex *pc, const Qgs3DMapSettings &map, QgsPointCloud3DSymbol *symbol, float maxScreenError )
+  : QgsChunkedEntity( maxScreenError,
                       new QgsPointCloudLayerChunkLoaderFactory( map, pc, symbol ), true )
 {
   setUsingAdditiveStrategy( true );

src/3d/qgspointcloudlayerchunkloader_p.h

@@ -115,7 +115,7 @@ class QgsPointCloudLayerChunkedEntity : public QgsChunkedEntity
 {
     Q_OBJECT
   public:
-    explicit QgsPointCloudLayerChunkedEntity( QgsPointCloudIndex *pc, const Qgs3DMapSettings &map, QgsPointCloud3DSymbol *symbol );
+    explicit QgsPointCloudLayerChunkedEntity( QgsPointCloudIndex *pc, const Qgs3DMapSettings &map, QgsPointCloud3DSymbol *symbol, float maxScreenError );
 
     ~QgsPointCloudLayerChunkedEntity();
 };

src/app/3d/qgspointcloud3dsymbolwidget.cpp

@@ -527,3 +527,8 @@ void QgsPointCloud3DSymbolWidget::blueAttributeChanged()
     }
   }
 }
+
+double QgsPointCloud3DSymbolWidget::maximumScreenError() const
+{
+  return mMaxScreenErrorSpinBox->value();
+}

src/app/3d/qgspointcloud3dsymbolwidget.h

@@ -32,6 +32,7 @@ class QgsPointCloud3DSymbolWidget : public QWidget, private Ui::QgsPointCloud3DS
     void setSymbol( QgsPointCloud3DSymbol *symbol );
 
     QgsPointCloud3DSymbol *symbol() const;
+    double maximumScreenError() const;
 
   private slots:
     void reloadColorRampShaderMinMax();

src/app/3d/qgspointcloudlayer3drendererwidget.cpp

@@ -50,6 +50,7 @@ QgsPointCloudLayer3DRenderer *QgsPointCloudLayer3DRendererWidget::renderer()
   QgsPointCloud3DSymbol *sym = mWidgetPointCloudSymbol->symbol();
   renderer->setSymbol( sym );
   renderer->setLayer( qobject_cast<QgsPointCloudLayer *>( mLayer ) );
+  renderer->setMaximumScreenError( mWidgetPointCloudSymbol->maximumScreenError() );
   return renderer;
 }
 

src/ui/3d/qgspointcloud3dsymbolwidget.ui

@@ -58,6 +58,23 @@
         </property>
        </widget>
       </item>
+      <item row="1" column="1">
+       <widget class="QDoubleSpinBox" name="mMaxScreenErrorSpinBox">
+        <property name="maximum">
+         <double>100000.000000000000000</double>
+        </property>
+        <property name="value">
+         <double>5.000000000000000</double>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="0">
+       <widget class="QLabel" name="label">
+        <property name="text">
+         <string>Maximum screen space error</string>
+        </property>
+       </widget>
+      </item>
      </layout>
     </widget>
    </item>