I'm trying to use ArcGIS Server's GeometryService to get an offset geometry from an input polyline. My application uses the webmercator projection, and when I call the Offset method, it returns a geometry that's offset by an amount different than what I asked for: I asked for 30.48 meters and the response was offset by about 24 meters.
I tried submitting the request using geometries in Geographic (WGS84) coordinates, but the response is a very strange set of coordinates (definitely not geographic) that break the map. The method doesn't appear to support an "outSpatialReference" parameter.
Does anyone have a solution for this? I believe the issue with the webmercator projection is that ArcGIS isn't calculating the distances correctly because of some internal conversion that isn't using geodesic calculations. I have no idea what it's doing when given geographic coordinates.
