Google half bakes WMS support

As has been reported all over the place, the latest Google Earth v4 beta now has “WMS” support.

In the 5 minutes i had a look, the following needs to be fixed

  1. The mandatory Service=WMS parameter is not attached to the online resource which causes some services to fail
  2. The is no support for layer subgroups as per WMS spec
  3. You cannot select the preferred image format when requesting (defaults to image/gif .. wheres my png!). Some services seem to pick png … ?
  4. The overlay never seems to be requested at the current, full extents .. for some reason?
  5. The [t] i’m assuming stands for transparency ?
  6. The client, out of courtesy, should always request any exceptions in image if the service supports it
  7. Generic HTTPS support is still broken for everything, including image overlays
  8. The client should really be able to interpret the bounding box and set the image overlays to start using the region KML functionality. If the average joe blogs adds a service, it would be for good measure to zoom to the envelope extents of that layer/service.

I know its beta, but truth be told i’m a bit dissapointed with the support. It really seems like the whole WMS feature was just something thrown in quickly, hidden in the depths of the image overlay -> refresh dialog. A lot of the points are very minor changes so i am hopeful the spatial guys at Google recognise the importance of good WMS support.

9 thoughts on “Google half bakes WMS support”

  1. I agree totally, but at least it’s a something.

    Here are some of my observations:

    1. You can tweak/edit the request URL and put what ever you need in there. Even though the interface doesn’t have a lot of flexibility as far as the GUI, at least you can hack together a ‘proper’ request string and it’ll work right. That means you can get your PNG! You can also specific a larger image to grab (I like 1024×1024 instead of 512×512)

    2. You can change the ‘View Bound Scale’ to 1 to make the WMS image be full screen.

    3. Several of the WMS servers on the provided list say they have no layers that GE can display. But if you chose them anyway, you can again build the URL by hand and it seems to work fine.

    I sure hope they polish this off. It COULD be REALLY cool…

  2. Hey thanks for the pointers eric. I will certainly have to sit down to play for a bit longer

    Of course you can always build the whole wms string yourself, but that makes having a wms “client” pointless!

  3. Chris:

    Not to be a GE apologist, but WMS support is something that, while important to we in the GIS community, is something the mass market may not really “get”. So not making the option front-and-center in the menu scheme is (a little) understandable. (And anyone used to XP or the most widely used desktop GIS is certainly used to having to deal with multi-tiered menus and obscurely located dialog boxes).

    Actually, my biggest disappointment is that the WMS implementation didn’t use any of the new Regions functionality–Jason Birch’s sample scripts provide a good glimpse of what’s possible in that realm.


  4. Actually, i’d have to disagree Brian. Check out the worldwind forums and WMS is one of the more popular features since it has been added … even for the non “GIS” professionals.

  5. I can’t make v1.3.0 servers work either.
    I disagree that errors should be displayed in the image. Instead an XML exception should be requested and returned to the user. Usually these exceptions can give you a better idea of what is wrong than the very limited error-message GE gives you. Placing error messages in an image is a really poor way of handling errors.

  6. TNTmap uses a kml reflector with on region based refresh, supports 1.3.0, imagetype selection (does default to gifs if the WMS has it, as google earth has poor png support)

    The locator view is used to show extents of the data as you mouse over the layers list before selecting the layers (or after)

    Check out what can be done via the onregion based refresh
    load it into your web pane of google earth use the sites pane to select a wms, then select layers and click the GE icon.

  7. One thing worth noting the on region refresh as implemented has some problems for layers with
    transparency… essentially the lower resolution
    images are still visible around the edges of higher resolution “updates” which are overlayed on top…
    What is needed is a way to say replace the main regions information with the contents of the results of this set of subregions, if that makes any sense to anyone?

Comments are closed.