AGSRaster PNG support

Question

I am unable to load a spatially enabled raster .png file into my map. The raster is made up of three files: * sketch.png * sketch.pgwx * sketch.png.aux.xml It loads fine in ArcMap. In attachment "ArcMap.png", the red lines are coming from the raster. By using raster.load(completion: ) to set my own completion block, I was able to see that it is getting an error: Failed to open raster dataset: /Users/Worth/Library/Developer/CoreSimulator/Devices/5690DA36-3E43-4DE1-881A-CF85BE5E2C43/data/Containers/Bundle/Application/79766C92-DBAD-4169-86AC-1CAECD4FABC9/testMapView.app/sketch.png Here is my ViewController.swift source code: import UIKit import ArcGIS class ViewController: UIViewController { @IBOutlet weak var mapView: AGSMapView! private var map: AGSMap! private var raster: AGSRaster! private var rasterLayer: AGSRasterLayer! override func viewDidLoad() { super.viewDidLoad() // create map with assigned spatial reference "web mercator (alternate sphere)" self.map = AGSMap(spatialReference: AGSSpatialReference.webMercator()) // assign a basemap to map self.map.basemap = AGSBasemap.topographic() // create raster self.raster = AGSRaster(name: "sketch", extension: "png") // for debugging, verify we can load the raster self.raster.load(completion: { (error: Error?) -> Void in if let error = error { print(error.localizedDescription) } }) // create raster layer using the raster and name it self.rasterLayer = AGSRasterLayer(raster: self.raster) self.rasterLayer.name = "sketch raster" // add rasterLayer to the map's operationalLayers self.map.operationalLayers.add(self.rasterLayer) for case let layer as AGSLayer in self.map.operationalLayers { print("\nSpatial reference for raster layer "\(layer.name)":") if let spatialReference = layer.spatialReference { print(" WKID = \(spatialReference.wkid)\n") } else { print(" \n") } } // assign map to mapView self.mapView.map = map // zoom to hard-coded Esri Charlotte office location where raster should appear let point = AGSPoint(x: -8992543.0, y: 4177500.0, spatialReference: AGSSpatialReference.webMercator()) let viewpoint = AGSViewpoint(center: point, scale: 2400.0) mapView.setViewpoint(viewpoint) // use KVO on drawStatus to know when it thinks it is finished drawing mapView.addObserver(self, forKeyPath: "drawStatus", options: .new, context: nil) } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() } override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) { guard let keyPath = keyPath else { return } if keyPath == "drawStatus" { if mapView.drawStatus == AGSDrawStatus.completed { guard let viewpoint = self.mapView.currentViewpoint(with: AGSViewpointType.centerAndScale) else { return } print("\ndrawStatus == .completed") guard let point = viewpoint.targetGeometry as? AGSPoint else { return } print("point: (x: \(point.x), y: \(point.y)), scale: \(viewpoint.targetScale)") } } } } ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ What is the best way to load a .png file as a raster in ArcGIS Runtime SDK for iOS? ArcMap.png DuncanHornby_0-1644267188937.png

WorthSparks · Answer

Yes. The sample you mention was one of my starting points. However, it only establishes the mapView's spatial reference from the raster itself, which doesn't show it being placed in the world based on its world file. I was able to get my PNG to appear at (0,0). I never was able to get it to appear where the world file and .aux.xml file placed it in ArcMap.

I hate to say it, but I gave up trying. It was becoming more and more evident that a raster was the wrong tool for what I was trying to do. So I switched to using a superimposed UIView with a subview for each PNG. That gave me the ability to apply transformation to each PNG based on current mapView viewpoint. The result keeps each PNG spatially accurate on the map, which, for what I need, looks and performs a lot better anyway.

YueWu1 · Answer

Hi Worth Sparks,

Have you checked about this sample that we provide on github, that using AGSRGBRenderer:

arcgis-runtime-samples-ios/RGBRendererViewController.swift at master · Esri/arcgis-runtime-samples-ios · GitHub

WorthSparks · Answer

I moved the spatial reference checking into the completion block and it worked. Thanks! So now I know it is reading the auxiliary file.

It still is not placing the raster in the correct location. I found it placed where the top-left of the raster is at (0,0) in coordinate space (off the coast of Africa). So even though it is reading the auxiliary file (.aux.xml), it doesn't seem to be honoring the target ground control points (<TargetGCPs> in the .aux.xml file).

Also, it is not honoring the alpha band in the .PNG file. I've been trying to find something in the documentation about enabling the alpha band, like with AGSRGBRenderer but have had no luck yet.