[IGSTK-Users] How to make complete use of VTK in IGSTK?

[jochen17 at hushmail.com]

Hey guys!

I'm pretty new to developing with IGSTK and especially new to this 
mailing-list, so hello everybody! My goal is to write some 
visualizations, that would help a surgeon identify critical 
objects, by highlighting them in the 3D scene. Since I want to 
explore the advantages of different methods for highlighting I want 
to write several different visualizations for the same objects and 
compare them. Because of this, I have a question about using VTK 
with IGSTK.

IGSTK uses SpatialObjectRepresentation classes to draw elements on 
the screen, it therefore uses the VTK framework. Also, IGSTK 
provides very basic methods to change the appearance of those 
elements (like SetColor or Set Opacity). Let's say I wanted to take 
it one step further and use VTK to do things like drawing contours 
around those elements, how would I do this with IGSTK in an elegant 
way? 

Is it possible to change the look of the elements by simply using 
GetActors() and modifying them? The problem I seem to get with this 
is, that the AddActors method is protected, which means I can't 
access it from where I create my SpatialObjects. Can I even apply 
the changes I made?

I came up with the possibility to completely write my own 
ObjectRepresentation classes and add methods that would make use of 
VTK. By doing so I could access the AddActors method. But it seems 
to me that this is not the most elegant way of doing things like 
this, since I would have a lot of redundant code.

Thank you very much!
Sincerely, Jochen