On Sun, Nov 23, 2008 at 11:20:56PM +0100, Christian Hackl wrote: > Hi, > > This is probably a newbie question, but since I cannot figure out the > answer even after days of reading docs, searching the archives and > studying examples, I thought I'd just ask, so here we go: > > How does one use a Vector layer upon an OSM base layer? > > All the working Vector examples I've seen use base layers other than > OSM. Copying the entire example code with just replacing the base layer > yields wrong results. No points or lines are visible anymore, or they > all appear centered at the equator no matter which values are chosen as > coordinates. > > I'm pretty sure that the problem has to do with projections, but as far > as that topic is concerned, I'm completely lost, both on theory and on > the practical part. I've tried to set the correct projection for OSM, > but none of my trial & error attempts worked. Any hints or reading > material on projections in OpenLayers would be very appreciated.
http://docs.openlayers.org/spherical_mercator/#working-with-projected-coordinates > > Here's a simplified example of my problem: > > function init() > { > var map = new OpenLayers.Map("map"); > map.addControl(new OpenLayers.Control.LayerSwitcher); > > // the following uses WMS and *does* work: > // map.addLayer(new OpenLayers.Layer.WMS("OpenLayers WMS", > // "http://labs.metacarta.com/wms/vmap0";, {layers: 'basic'} )); > > // the following uses OSM and does *not* work: > map.addLayer(new OpenLayers.Layer.OSM.Osmarender("Osmarender")); > > var vectorLayer = new OpenLayers.Layer.Vector("Just a point..."); > var point = new OpenLayers.Geometry.Point(-111.04, 45.68); point.transform(new OpenLayers.Projection("EPSG:4326"), new OpenLayers.Projection("EPSG:900913"); > var pointFeature = new OpenLayers.Feature.Vector(point); > > map.addLayer(vectorLayer); > map.setCenter(new OpenLayers.LonLat(point.x, point.y), 5); > vectorLayer.addFeatures([pointFeature]); > } Regards, -- Christopher Schmidt MetaCarta _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users
