NA-MIC Project Weeks

Markups redesign and new markups for curve, line, and angle measurement

Key Investigators

Davide Punzo (remotely)
Andras Lasso (Queen’s University, Canada)
Sara Rolfe (University of Washington, USA)
Kyle Sunderland (Queen’s University, Canada)
Jean-Christophe Fillion-Robin (Kitware)
Steve Pieper (Isomics)

Project Description

Objective

Fix all issues and improve markup fiducial points widgets
Add angle, line, and curve widgets

Approach and Plan

Complete redesign of markups is needed, due to high complexity and low performance of current implementation. The main change is that we give up on relying on widgets provided by VTK, as they use unnecessarily complex, inconsistent design, extremely slow, and lack essential features. See more information on the Markups improvements Slicer labs page.

The new infrastructure relies on:

storing all data in standard VTK data objects, which are stored in MRML nodes and directly shared between widgets
widgets are rendered using hardware accelerated glyph filter
one (or few) VTK actor for each widget (not adding a new actor for each markup point as before)

Plan is to integrate the reworked markups infrastructure and new markups during the project week then continuously fix issues and add the numerous planned features.

Progress and Next Steps

Davide Punzo has reworked markup point list widget:

Pull request

Points video

and added angle, line, open curve, and closed curve widgets.

Open Curve video
Andras and Sara tested and reported errors Davide fixed them
17 of 27 known issues have been fixed. Open issues are mostly enhancements or problems in new features (not regressions in existing features).
Necessary VTK updates (double-click and selection event support) merged into Slicer/VTK
Remaining issues with point picking: slow when using cell picker, screen flickers when using prop picker. We’ll use one picking manager for all markups in a view. Maybe we can later implement one picking manager for all objects in a view.
Next steps: merge Slicer updates during next week.
Several important changes depend on this (we don’t want to switch to git, deprecate old VTK/ITK versions, move to git … until this is completed).