GeometryEngine fails to project valid points, returning NaN

RobertBares — Sat, 11 Dec 2021 18:01:09 GMT

Steps to reproduce:

Load a world map with the following spatial reference:

PROJCS["WGS_1984_Web_Mercator_Auxiliary_Sphere",GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Mercator_Auxiliary_Sphere"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",0.0],PARAMETER["Standard_Parallel_1",0.0],PARAMETER["Auxiliary_Sphere_Type",0.0],UNIT["Meter",1.0]]

Enable wrap-around at the 180 degree meridian

Center the map on the 180 degree meridian at the equator (near baker island), configuring the map extent so the bottom left and top right corner are as follows:

bottomLeft: Point [m_attributes=[1.9449581424337383E7, -626899.6119120895], m_description=com.esri.core.geometry.VertexDescription@7c5d0f85]
topRight: Point [m_attributes=[2.0623654149388406E7, 706162.1279895945], m_description=com.esri.core.geometry.VertexDescription@7c5d0f85]

Attempt to extract and convert these points to WGS84, using:

Point bottomLeft = mMapView.toMapPoint(0, mMapView.getHeight());
Point topRight = mMapView.toMapPoint(mMapView.getWidth(), 0);
SpatialReference WGS84 = SpatialReference.create(SpatialReference.WKID_WGS84);
Point wgs84BottomLeft = (Point)GeometryEngine.project(bottomLeft, mMap.getSpatialReference(), WGS84);
Point wgs84TopRight = (Point)GeometryEngine.project(topRight, mMap.getSpatialReference(), WGS84);

Expected result: Two valid WGS84 points

Actual result:

wgs84bottomLeft: Point [m_attributes=[174.71856263209403, -5.622489445477077], m_description=com.esri.core.geometry.VertexDescription@7c5d0f85]
wgs84topRight: Point [m_attributes=[NaN, NaN], m_description=com.esri.core.geometry.VertexDescription@7c5d0f85]

This issue becomes even worse if you move the extent further east, and you can easily get into a situation where both points return NaN.

Re: GeometryEngine fails to project valid points, returning NaN

RobertBares — Tue, 24 Mar 2015 11:35:54 GMT

Fixed using normalizeCentralMeridian from the latest version of the SDK. See bottom half of this page for more details: Enable wrap around—ArcGIS Runtime SDK for Android | ArcGIS for Developers

topic GeometryEngine fails to project valid points, returning NaN in ArcGIS Runtime SDK for Android Questions

GeometryEngine fails to project valid points, returning NaN

Re: GeometryEngine fails to project valid points, returning NaN