Regions Window Tab
KML Regions are a powerful feature that allow Google Earth to
stream your data in pieces instead of
as a whole. If you have large datasets, this might be the only way to display your data. Likewise,
if you want your data to appear only when the user’s camera is at a certain altitude, you have to
use regions as well. All other data is either visible or not visible.
General Region Options
• Fade Effect – As your layer becomes visible
because its region is active, Google Earth can apply a fade in/fade out effect that changes the
translucency of your data. Visually this appealing however, make sure to test
this option since its computationally intensive and may cause GE to slow down quite a bit
• Level of Detail – This is an advanced setting that
normally you would not change at all.
However, in general, if you want your layer to appear sooner (e.g. at a higher altitude), you can
decrease “Minimum” value. If you set it to “0”, your region will always be visible (thus obviating
the need for the region in the first place) Please click on the “more info” link to find out more
about LOD settings and Regions in general
• Region Level – These course grain levels are
similar to the levels of map tiles used in
Google maps or MS Virtual Earth. Each level represents an approximate map scale although setting
the Min/Max LOD settings above will alter at what map scale your data appears. In general, you can
the value that Arc2Earth sets for you automatically (which is
based on the current map scale in
ArcMap) however it is good practice to use the “Visualize” option to see how your data will be
Visualize Window – When you click on this button, a new
window with a map containing your
layer is opened. Red lines are displayed that show where your data will be regionalized. You can
zoom and pan the map and reset the Region level to see the affects on your region sizes.
Vector Regions – If you have a vector based layer and
choose to export it as vectors (on the
Layer General tab), your regions will consist of clipped features that fit exactly in your regions.
This ensures that your data is displayed evenly and efficiently as you move around Google Earth. If
you choose to export your vector layer as rasters (again, using the option on the Layer general
tab), then the regions will include a single GroundOverlay of that area. This is a good way to
preserve symbology however you should consider always exporting to vector regions
Raster Regions – For raster layers, a single Ground
Overlay is used for the region. This is
different from the Superoverlays created by the Tile Exporter in that only a single levels of
ground overlays are created. With Superoverlays, multiple levels are created with each successive
level containing a higher resolution of the image.