AnsweredAssumed Answered

Buffer distance not correct

Question asked by PinnGIS on Jan 27, 2014
Latest reply on Jan 28, 2014 by PinnGIS

I'm having difficulty creating an accurate buffer of a polygon.  I can request the buffered geometry and display the respective graphic just fine, but when I measure the distance of the buffer to the original polygon (using the esri measure dijit) the distance is not the same as my input distance.

When in ArcMap, I buffer the same polygon by the same distance and I get a different buffer than I get from the js Geometry Service so I'm fairly certain that my problem lies with the Geometry Service not the Measurement dijit.

var buffDist = dom.byId("BuffDist").value; var gph = graphicArray[0]; var gs = new GeometryService(""); var params = new BufferParameters(); params.distances = [buffDist]; params.unit = GeometryService.UNIT_KILOMETER; params.bufferSpatialReference = map.spatialReference; params.outSpatialReference = map.spatialReference; params.geometries = [gph.geometry]; gs.buffer(params, function (result) {});

My workflow is quite standard.  My input geometries are from a graphic that I received from a user click on the map.  The map spatial reference is web mercator (102100), which I thought might be causing the problem so I have been experimenting with converting web mercator to geographic but I have not had any luck getting a successful return from the Geometry Service.

Anyone have any ideas what is causing the buffer to be wrong?