Last time I asked about WMS, KakaduDreamer pointed me towards his http://earthalerts.manyjourneys.com/web/, which led to me throwing up an overlay example. Not base layers, but it might be helpful. http://lyceum.massgis.state.ma.us/wiki/doku.php?id=googlemapsv3:home
As Davide mentioned, it takes advantage of the data being in a WMS, rerequesting @ different zoom levels, etc. Coordinate conversion is implemented in a Custom Projection which has methods fromLatLngToPoint, fromDivPixelToLatLng, and just to be sure, fromDivPixelToSphericalMercator All that said, this creates an overlay, not a replacement base layer. Esa has some examples with putting OpenStreetMap as a base layer here. (He also shows how you'd reconstruct existing base map types.) The syntax looks very similar for baseMaps and Overlays, so you could probably use similar logic to my WMS example. http://koti.mbnet.fi/ojalesa/v3/osm_dual.htm Hopefully thats of some help. Josh On Thu, May 27, 2010 at 7:09 AM, Davide Cremonesi <[email protected]> wrote: > Hello everybody, > I must say that I don't like this solution based on GroundOverlays (of > course you might well be happy with it and ignore my message :-). > The problem I see is that once you get the image at the largest scale it > gets scaled by the client at lower scales (zooming in) and resolution get > worst and worst. The advantage of a WMS service is that images are created > on the server at different scales and extents modifying the BBOX parameter > in the URL. > What you need to do is convert Google tile x, y, and zoom into a suitable > WMS URL. > > Here is a good starting point (based on v2 API): > http://blog.kylemulka.com/2005/08/wms-in-google-maps/ > > Cheers, > Davide > > PS if I have some time I will try to make an implementation myself and make > it pulbic here on the forum > > 2010/5/27 Jack Berberette <[email protected]> > > Wow...thanks for all of your effort in this William! I'll definitely work >> on this when I get back to the office tomorrow. You've really gone above >> and beyond for us and we truly appreciate it. >> >> Thanks, >> >> Jack >> >> >> On Wed, May 26, 2010 at 10:30 PM, William <[email protected]> wrote: >> >>> On May 27, 6:03 am, Jack Berberette <[email protected]> wrote: >>> > >>> > is it posible to tile the imagery so not matter what area you >>> > wanted to look at you could see the cloud cover? >>> > >>> >>> the help file says you can select Google Mercator map projection (EPSG: >>> 900913), but I only got blank images when I tried that option. >>> >>> Since the JPG files are small, it might be ok to use the Ground >>> Overlay with a 50% extended border around the image, and then update >>> the image whenever the zoom changes or the user pans outside this >>> area. >>> >>> http://nowcoast.noaa.gov/help/mapservices.shtml?name=mapservices >>> >>> WMS Map Projections & Spatial Reference Systems (SRS) >>> The WMS standard requires that every request must include the "SRS" >>> parameter, which specifies the identifier of the desired Spatial >>> Reference System (projection) of the requested map image. In addition >>> to the standard geographic projections, nowCOAST map services allow >>> requests to be made in the Web Mercator projection, which is used by >>> many popular online mapping services such as Microsoft Bing and Google >>> Maps. When overlaying nowCOAST data with Google Maps or Microsoft Bing >>> imagery, it is recommended to use either the "EPSG:102113" or "EPSG: >>> 900913" SRS values in your requests. Otherwise, the most commonly used >>> projections are NAD83 and WGS84. >>> >>> SRS values can be specified in a WMS request by including >>> "&SRS=IDENTIFIER" in the target WMS URL, where "IDENTIFIER" is >>> replaced with one of the supported SRS Identifier values, listed >>> below: >>> EPSG:4267 North American Datum of 1927 (NAD 27) >>> EPSG:4269 North American Datum of 1983 (NAD 83) >>> EPSG:4326 World Geodetic System 1984 (WGS 84) >>> EPSG:102113 Web Mercator (ESRI Identifier) >>> EPSG:900913 Web Mercator (Google Identifier) >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Google Maps JavaScript API v3" group. >>> To post to this group, send email to >>> [email protected]. >>> To unsubscribe from this group, send email to >>> [email protected]<google-maps-js-api-v3%[email protected]> >>> . >>> For more options, visit this group at >>> http://groups.google.com/group/google-maps-js-api-v3?hl=en. >>> >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "Google Maps JavaScript API v3" group. >> To post to this group, send email to >> [email protected]. >> To unsubscribe from this group, send email to >> [email protected]<google-maps-js-api-v3%[email protected]> >> . >> For more options, visit this group at >> http://groups.google.com/group/google-maps-js-api-v3?hl=en. >> > > -- > You received this message because you are subscribed to the Google Groups > "Google Maps JavaScript API v3" group. > To post to this group, send email to > [email protected]. > To unsubscribe from this group, send email to > [email protected]<google-maps-js-api-v3%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/google-maps-js-api-v3?hl=en. > -- You received this message because you are subscribed to the Google Groups "Google Maps JavaScript API v3" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-maps-js-api-v3?hl=en.
