[idvusers] idv classes for a vehicle track?

I have a dataset of the form


where TYPE can have values say A or B. I would like to plot this using the idv classes such as LineDrawing, etc, such that the lat, lon points are joined by lines, but the actual points reflect the A or B type. Imagine that for types A we want to draw a cross-hair, whereas for types B we draw a filled circle. I do not want to distinguish A from B using color, since there are many of these 'vehicle tracks' on one display and the vehicles are already distinguished using a color per vehicle.

I must add that the idv api classes are a great step up in abstraction from the native visad ones. Great job Don and Jeff!

Stuart Maclean