QML Map: Large Number of Displayed Items

I have a performance issue when displaying large volumes of MapItems on a map provided by the QML location module. I already asked a question here ( https://forum.qt.io/topic/79229/large-amount-of-qml-mapitems ), but nobody could help me, so I wanted to try it here once. I also found this question ( How do I use the QML / QtLocation module to display a lot of offline data on a map? ), But before adding another dependency, I wanted to make sure my code could be improved so that QML could handle this situation without any help.

I am currently trying to plot a large number of items on a QML map (30,000 - 120,000 points). These elements should update based on the position of the QSlider. The performance drops a lot from about 1000 pips up, when I use 30,000 it takes a few minutes until the QML map displays all the data and is responsive again. I have a machine that is absolutely capable of doing this task in general, so I think the problem is with QML. I am using Qt 5.8.

Is there a way to improve this performance, or is it just not possible with a QML Map to display so many MapItems at once? I tried MapCircles, Polylines, Polygons, and MapQuickItems with images, but it seems to me that the performance issue only occurs when adding this number of MapItems, since I did not see a significant difference in processing time between these types.

I have more data in the rendered map that shouldn't be refreshed every time the QSlider is moved. Although I tried to just clear all MapItems and add new ones for performance tests, even that did not improve performance.

My code (a bit abstracted) looks like this:

///-------------- Widget.cpp-----------------///
void ProcessInput(int qslider_pos) {
      QVariantList lat_vec;
      QVariantList lon_vec;

      // Fill vectors with lateral and longitudinal positions
      // ...

      // Clean current points on map and draw new ones
      SendToQmlFuncRemovePoints();
      SendToQmlFuncAddPoints(lat_vec, lon_vec);
}

void QmlConnector::SendToQmlFuncRemovePoints()
{
    QVariant returnedValue;
    QMetaObject::invokeMethod(QmlMapSingleton::instance()->GetRoot(), "remove_points",
        Q_RETURN_ARG(QVariant, returnedValue));
}

void QmlConnector::SendToQmlFuncAddPoints(QVariantList input_one, QVariantList input_two)
{
    QVariant returnedValue;
    QMetaObject::invokeMethod(QmlMapSingleton::instance()->GetRoot(), "add_points",
        Q_RETURN_ARG(QVariant, returnedValue),
        Q_ARG(QVariant, QVariant::fromValue(input_one)), Q_ARG(QVariant, QVariant::fromValue(input_two)));
}

      

        
        
        
      

    

...

///-------------- Map.qml -----------------///

Map {
     anchors.fill: parent
     property variant points: ({})
     property int pointCounter: 0

     Plugin
     {
        id: osmplugin
        name: "osm"
        PluginParameter { name: "osm.mapping.highdpi_tiles"; value: true }
     }

     Component.onCompleted: {
         points = new Array();
     }
    id: map
    plugin: osmplugin

    //Javascript functions
    function add_points(array_lat, array_lon) {
        var myArray = new Array()
        var component = Qt.createComponent("mapcircle.qml");
        for (var i=0; i<array_lat.length; i++)
        {
            var object = component.createObject(map, { "center": QtPositioning.coordinate(array_lat[i], array_lon[i]})
            map.addMapItem(object)
            myArray.push(object)
        }
        map.points = myArray
    }

    function remove_points() {
        var count = map.points.length
        for (var i = 0; i<count; i++){
            map.removeMapItem(map.points[i])
            map.points[i].destroy()
        }
        map.points = []
    }
}

      

        
        
        
      

    

...

///-------------- mapcircle.qml -----------------///
import QtQuick 2.0
import QtLocation 5.6

MapCircle {
      radius: 1
      border.width: 0
      color: 'green'
}