Topics for this session:

Information to the developer community about how these projects have approached developing their code for slicer3 (what's the architecture of their modules)
Feedback to the base developers about what was easy or hard in the code writing
What would they like to see in the slicer3 base and/or in VTK, ITK, KKWidgets, etc to make the module development more effective

DTI

Tractography is represented as a vtkMRMLFiberBundleNode. Display parameters are stored in a vtkMRMLFiberBundleDisplayNode, and storage (load/save) handled by vtkMRMLFiberBundleStorageNode. Basic operations of adding new fiber bundles, etc. are in vtkMRMLFiberBundleLogic.
vtkMRMLFiberBundleDisplayLogic is needed to create "hidden" slicer models that will be rendered in the MRML scene. Otherwise base classes would have to be heavily edited to handle tractography display using the display node.
There will be several slicer module units to handle tractography. The division will be by Load/Save/Display, Editing (to manually add, select, delete, or to use ROI selection), Seeding, etc.
Initial work is on the Load/Save/Display and the entire MRML infrastructure.

When adding a new module and a new datatype, it is difficult to find the places in Base code that must be edited.
It is also difficult to understand how the MRML callback happens, and how to set a new one up. It would be great to have a simple overview on the observers somewhere (or even the SVN web for easier code navigation).
If a vtkMRMLNode inherits from another one used in slicer (for example mine inherits from the modelNode currently) then the subclass will show up on all of the superclass menus. This is because the vtk "IsA" function is used rather than a direct match. I believe this is feature that is not desired.

==Hisotory of our involvement

Summer 2006: Haying Liu joined the core development team and implmented MRAblation module from the Slicer 2.6. There he
- learned the architecture of Slicer 3.
- get familiar with KWWidgits

Fall 2006: Haying Liu implemented IGTDemo module. There he
- contributed vtkIGTDemoLogic and vtkIGTDemoGui in the Base.
- Modiy CMake to enable link external library opentracker

- December 2006
- Two additional members joined IGT-Slier3 task force
  - Simon DiMaio representing prostate robot project [PI Tempany1R01CA111288]
  - Raimondo Sierra representing Neuroendoscope project [PI Jolesz 5U41RR019703]

Implementation strategy for IGT-Slicer is discussed and preliminary design proposed (by Hata and Liu)