[IGSTK-Developers] Adding visualizations to IGSTK

[Görtler, Jochen]

Hello everybody,

As a result of my bachelor-thesis I have developed some visualizations that aim to help a surgeon during an operation, using augmented reality.  I think Sebastian Röhl demoed some of them during the IGSTK users meeting. They all take an ObjectRepresentation, or rather its vtkActor, as an input and generate i.e. NavigationWidgets for them or draw symbols to highlight those representations. 

This works by adding more vtkActors to the ObjectRepresentations ActorsList. At the moment I have written my own ObjectRepresentations, which derive from the igstkMeshObjectRepresentation. The visualizations are prepared in the  CreateActor() methods after the 'main' vtkActor was created. I don't know if this is the best (intended) way of handling this and I think a more general approach would be better.

There are some limitations to this way of doing it:

- The way SetColor/SetOpacity work, one can't set the color/opacity of those new actors independently from the main object.

- I haven't found a clever way to add/remove those additional actors during runtime, which would be interesting for connecting/disconnecting visualizations with the corresponding ObjectRepresentations.

- It is difficult to add more than one visualization to each representation without getting code that is really dependant and hard to maintain. The way the different vtkActors are stored in the ActorsList should be hidden from the user.

- It would be good to have the visualizations working for all ObjectRepresentations, not only MeshObjectRepresentations.

If you are interested, I would like to share my code and integrate this functionality with IGSTK, but it would require some underlying changes to the ObjectRepresentation classes. Maybe you have an idea how this could be accomplished?

Best regards,

Jochen