Visualization

3D Geometry Visualization

Braviz relies on VTK for 3D visualization. The classes and functions in this module are meant to wrap common vtk tasks in order to make it easier to implement brain visualizations. The main modules used for this purpose are:

• Simple VTK (simple_vtk) : Several utilities that help displaying data in vtk. Includes the SimpleVtkViewer, a lightweight viewer useful for testing. see Simple VTK Visualization
• Subject Viewer (subject_viewer) : Implements a powerful viewer and Qt4 Widget which directly requests data, and handles subject and space changes. see Subject Viewer

The module fmri_view contains some low level utilities for displaying fMRI data. The module checkerboard_view implements a widget that shows two images in a checkboard pattern. It is intended to check the registration between different modalities.

Statistical Visualization

One of the strengths of braviz is combining scientific visualizations and statistical visualizations. For visualizing tabular data the following options exist.

Matplotlib based visualization

The most direct way to visualize statistical data is using the seaborn library. The module matplotlib_qt_widget wraps several of seaborn plots into an interactive qt widget.

Experimental D3 based visualization

There is some experimental support for web-based visualizations using the D3 library, which are served from a tornado web server . These visualizations can be displayed in Qt applications using a QWebView but the performance is not optimal. It is better to display them in a full browser. We are still working on tightening the integration between this kind of visualizations with the rest of the system.

See the module d3_visualizations.