Elevation in 2D

NorbertThoden

Hi All!

I´m able to use the screenToLocation/screenToBaseSurface call to get the appropriate location containing x and y and also the desired elevation available at z().

The necessery assignment of the elevationSourceUrl is simple and it worsk for 3D - fine.

But whats about 2D:

Eric Bader gave me the hint to have a look at the Surface class - Surface Class | ArcGIS for Developers and its locationToElevation method.

Unfortunatly i can´t get it work.

What i did:

1. create Esri::ArcGISRuntime::ArcGISTiledElevationSource per URL
   
2. create Esri::ArcGISRuntime::Surface using the elecationSources (as QList)
3. request elevation by
   
   1. connect locationToElevationCompleted to an appropriate slot (onLocationToElevationCompleted)
      
   2. call locationToElevation on that surface

but the result in onLocationToElevationCompleted is nan (not a number)

My questions are:

What is missing? Like:

1. Where do i have to call Loadable::load()?On Surface (cascading loading?) or every ArcGISTiledElevationSource directly? Or both?
2. Do i have to enable the single ArcGISTiledElevationSources? (setEnable())

I think there are many question for an essential problem, isn´t it?

Is there an example?

Thanks in advance!

Norbert

LukeSmallwood

Hi Norbert, I hope you are well. I don't believe we do have an example of this workflow currently - but I will recommend we add one as it seems like a useful workflow to me.

Here is some code I have put together to show how this could work. In this case I am creating a Surface and a single ArcGISTiledElevationSource. We have to manually load these since they are not added to the view in the same way we would for a 3D application.

Once these are loaded, I am connecting to the mouseClicked signal on the MapView, obtaining a location for that click and starting the operation.

I hope that helps,

Luke

    ArcGISTiledElevationSource* elevationSource = new ArcGISTiledElevationSource(

                QUrl(yourUrl), this);

    connect(elevationSource, &ArcGISTiledElevationSource::errorOccurred, this, [](Error error)

    {

        qDebug() << error.message() << error.additionalMessage();

    });

    m_surface = new Surface(this);

    m_surface->elevationSources()->append(elevationSource);

    connect(m_surface, &Surface::errorOccurred, this, [](Error error)

    {

        qDebug() << error.message() << error.additionalMessage();

    });

    connect(m_surface, &Surface::loadStatusChanged, this, [](LoadStatus loadStatus)

    {

        qDebug() << "loadStatus:" << static_cast<int>(loadStatus);

    });

    connect(m_surface, &Surface::locationToElevationCompleted, this, [](QUuid, double elevation)

    {

      qDebug() << elevation;

    });

    connect(m_surface, &Surface::doneLoading, this, [this](Error error)

    {

        if (!error.isEmpty())

            qDebug() << error.message() << error.additionalMessage();

        qDebug() << "loaded";

        connect(m_mapView, &MapGraphicsView::mouseClicked, this, [this](QMouseEvent& mouseEvent)

        {

            Point loc = m_mapView->screenToLocation(mouseEvent.x(), mouseEvent.y());

            qDebug() << "locationToElevation: " << loc.toJson();

            m_surface->locationToElevation(loc);

        });

    });

    connect(elevationSource, &ArcGISTiledElevationSource::doneLoading, this, [this](Error error)

    {

        if (!error.isEmpty())

            qDebug() << error.message() << error.additionalMessage();

        qDebug() << "elevationSource loaded";

        m_surface->load();

    });

    elevationSource->load();