topic Re: Loaded Raster Layer has a null WKID in Qt Maps SDK Questions

Loaded Raster Layer has a null WKID

imbachb — Mon, 18 Sep 2023 15:46:45 GMT

I'm using following geotiff raster layer sample dataset: swissALTI3D sample data - swisstopo

Direct download link: https://cms.geo.admin.ch/Topo/swissalti3d/swissalti3dgeotifflv95.zip

I would like to show this raster layer on top of a basemap. I initialize both like this, with 2056 being the spatial reference system the raster layer is based upon.

m_map = new Map(SpatialReference(2056), this); QUrl imageLayerUrl("https://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer"); auto baseLayer = new ArcGISMapImageLayer(imageLayerUrl, this); auto basemap = new Basemap(baseLayer, this); m_map->setBasemap(basemap); const QString filepath = defaultDataPath() + "/ArcGIS/Runtime/Data/raster/SWISSALTI3D_TIFF_CHLV95_LN02/0.5m/SWISSALTI3D_0.5_TIFF_CHLV95_LN02_2600_1196.tif"; Raster* raster = new Raster(filepath, this); m_rasterLayer = new RasterLayer(raster, this); m_map->operationalLayers()->append(m_rasterLayer);

The resulting map only shows the basemap and not the added raster layer. The raster layer does not report any errors.

When I do not load the basemap then the raster layer is visible.

When I log the raster layer's fullExtent its json representation looks like this:

// auto envelope = m_rasterLayer->fullExtent(); // qDebug() << envelope.toJson(); { "xmin": -0.5, "ymin": -6999.5, "xmax": 6999.5, "ymax": 0.5, "spatialReference": { "wkid": null } }

implying that there's an issue with the raster layer's spatial reference.

I can load this raster layer perfectly into ArcGIS Pro where it automatically gets the correct spatial reference.
Does anyone have a clue on what I might be doing wrong here?

Many thanks!

Re: Loaded Raster Layer has a null WKID

imbachb — Tue, 19 Sep 2023 07:36:51 GMT

The raster layer's `aux.xml` looks like this:

Could it be that unlike ArcGIS Pro the ArcGIS Maps SDK requires a `SRS` node in the auxiliary file as seen here Showing a georeferenced local raster · GitHub?` When I add a `SRS`, the raster layer is displayed on the map...

If so, how do I get the correct value for this `SRS` node into the auxiliary file? Can ArcGIS Pro generate it?

Re: Loaded Raster Layer has a null WKID

imbachb — Tue, 19 Sep 2023 13:28:21 GMT

I found the corresponding .prj file here spatialreference.org | EPSG:2056 which I can use to add the SRS node to the auxiliary file. This seems to work.

However, when I use ArcGIS Pro to create a mappackage from this raster layer and try to load and display the mappackage, the raster layer again is not shown, again with its fullExtend having a null WKID. Other layers such as a graphics layer from the mappack are shown no problem...

Following is a log of the map's and the raster layer's properties:

MapView WKID: 2056 Map WKID: 2056 Operational "SWISSALTI3D_TIFF_CHLV95_ZURICH_2m" WKID: 0 LayerType: LayerType::RasterLayer Extent: {"xmin":-0.5,"ymin":-6999.5,"xmax":6999.5,"ymax":0.5,"spatialReference":{"wkid":null}} Operational "Graphics Layer" WKID: 2056 LayerType: LayerType::FeatureCollectionLayer Extent: {"xmin":2684671,"ymin":1250214,"xmax":2690057,"ymax":1255309,"spatialReference":{"wkid":2056}}

Re: Loaded Raster Layer has a null WKID

GuillaumeBelz — Wed, 20 Sep 2023 16:56:47 GMT

Hello,

I can reproduce the problem with raster layer. I'm investigating and I'll come back.

Re: Loaded Raster Layer has a null WKID

GuillaumeBelz — Wed, 20 Sep 2023 18:54:31 GMT

Hello,

Non-common transformations are supported using projection engine data. All details are explained here https://developers.arcgis.com/qt/spatial-and-data-analysis/spatial-references/ and you can download data here https://developers.arcgis.com/downloads/#pedata.
You can use `TransformationCatalog::setProjectionEngineDirectory` https://developers.arcgis.com/qt/cpp/api-reference/esri-arcgisruntime-transformationcatalog.html#setProjectionEngineDirectory to set the path to transformation data.

const QString dataPath {"path/to/Projection_Engine_Data_200_2_0/pedata"}; TransformationCatalog::setProjectionEngineDirectory(dataPath);