Hi Gopal,
I am currently working on the related subject of multiple display/multiple
data rendering to promote interactive response.
My task involves displaying meteological data both three-dimensionaly
and two-dimensionally on a 3D Globe, and on map projections, allowing
user to (1) switch between mode of display, (2) switch on/off displayed
data, and (3) add/remove data as needed.
So far, it has been a rewarding experience with VisAD.
At the moment, I have difficulty in acertaining the sequence of
rendering the data in the 2D display to ensure certain image stay
on top.
The "overlays" involved allowing the user to switch on/off data
(via data references) like coastlines, latlon lines, satallite
images, GIF file textures, radar images contour lines, tracks etc.
VisAD had all the functionalities for this purpose, but to
put them together, there is a need to manage all the individual
ScalarMap and ConstantMap mappings, apart from adding GUI controls.
For examples, individually added dataReference (by addReferences()
or addReference()) may have already added etc etc...
How can I help you?
cheers
Ng Say Teong