I’d like to describe my experience with the Slicer markups module and suggest some improvements.
I wanted to place some fiducials and export them as a list. I opened the Markups module and click the first icon “Create Fiducial Markup” and place it in the viewer. The markup appears in the list and I repeat this for a bunch of landmarks. Then I want to save the list of fiducials/markups but seem to be only able to save them individually.
I asked my walking slicer reference aka Fernando for help and he explained to me that I was creating markup nodes/lists with one element rather than adding new elements to an existing list. The fact that I need to use the icon in the menu bar to place individual fiducials is not very intuitive and as the icons are virtually the same I did not expect different behaviour. It is especially confusing as the viewer shows what I expect: every time I click the icon I can place a fiducial but the creation of a list on top is not transparent.
Within the markup module, I would suggest to have a button to add a markup node/list with appropriate description and then separate buttons to add elements to this node/list. It might also be reasonable to move the functionality to add elements into the “control points” sub module (which I didn’t look at initially because I thought I found the function I needed). I would also expect to have the same buttons within the module window as in the menu bar (I did not expect that some functionality is only available outside the relevant module).
I hope this is understandable and that it could be used to improve Slicer.
PS I am using Slicer 4.11.0-2020-01-30 r28751