[OpenLayers-Users] Problems with scaling when Virtual Earth is the
base layer?
Richard Marsden
richard at winwaed.com
Mon May 12 20:23:04 EDT 2008
I don't know if anyone has seen this, or know of a workaround, but I'm
finding that if I zoom in too far with a Virtual Earth base layer, then
the other layers are not plotted.
Eg.
http://www.ecomapcostarica.com/map/map_test_ve.shtml
( I've found problems when trying to switch base layers between
MapServer WMS and Virtual Earth. It will switch from VE to MPS
perfectly, but not back again. My solution was to have two pages: one
for each base layer. The above page is the draft version of the VE page)
The default zoom (also duplicated with the Leaves and Lizards zoom
option) plots at the maximum zoom that works. What you see is a KML
layer, on top of a raster image and a 'stream' vector layer (both from
MapServer WMS). No VE should be visible, but if you pan to the north VE
should be visible.
In fact we're zoomed in too far and VE shows the "forbidden camera" icon
indicating that sufficiently detailed images are unavailable. This is
to be expected. However if we zoom in one step further (eg. by scrolling
the mouse wheel one click), then OpenLayers appears to 'hang' with the
VE layer and does not show the other layers.
This is actually quite limiting for this application, because virtually
everything of interest will be plotted in the red KML polygon!
So does anyone know of a workaround, eg. is it possible to make the VE
base layer automatically appear and disappear when zoomed in very far?
As an aside, the working non-VE version which uses public outline SHP
data instead, can be seen here:
http://www.ecomapcostarica.com/map/index.shtml
We shall be in the field in two weeks time, and hope to update the
map(s) whilst we're out there. Yes Wifi has even reached the rainforest!!
Richard
--
Richard Marsden
Winwaed Software Technology LLC
http://www.winwaed.com
Tools and Add-ins for MapPoint - http://www.mapping-tools.com
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