Navid,
The API doesn't expose functionality to access the 3D model's geometry/
material data. You could, however, pull this information out manually
with some work:
Model KMZ files are simply ZIP files that contain a doc.kml file as
well as .DAE files (in COLLADA format -
http://en.wikipedia.org/wiki/Collada)
that describe the model geometry. Since the COLLADA format is XML-
based, you could use any XML parser (i.e. GXml -
http://code.google.com/apis/maps/documentation/reference.html#GXml) to
pull out the necessary details.
- Roman