[vtkusers] Newbie rendering question

[Johnson, Michael L.]

I am new to VTK, but I can see about a million applications for me already!
I have what may be a simple question.  Here's my situation:

I already have an application that renders a map in different
projections/sizes/etc.  This is the main window.  Now I want to use VTK to
render an additional layer of structured point data on top of it (for
example, a population density color chart, or topographic contour lines).  I
want to use, for example, the vtkContourFilter to generate the contours.
This all (drawing the contours BY THEMSELVES) works awesome in my "test app"
which I adapted from one of the samples using the win32 opengl window
renderer.  Now is where it gets hard:  Instead of rendering it to an openGL
window, I want to take the data and render it (including
stretching/transforming it due to different map projections!) ONTO my map
view, which already has other stuff on it (example:  geographic boundaries,
etc.)  Since I am new to VTK, it is not obvious to me where the "new" code
needs to lie.  Are there other examples of where this might have already
been done?  Note that my current app does NOT use openGL, just straight
win32 calls.  And note that I do not want to take all of our current code
and change it to use VTK (IE, I want to keep the same map rendering code
that I already have!)  Is there some way to just "intercept" the render
calls, then "transform" them?

I am also hoping maybe the two main VTK books might cover this; I ordered
both from Amazon.com today, but Amazon says delivery sometime between Dec.
29 and Jan. 9, and I don't have that long to figure this out.  Thanks in
advance for any help I get!!!!  

You guys have done an incredible job with this product!!!!

Mike Johnson