The ribbon method yields a segment that looks nicer and that allows labelmaps to be created. The segment’s volume was calculated to be 0.209cc, which is about half of what you said it is in MIM. This makes complete sense if we consider interpolation (i.e. the aforementioned end-capping, which is performed in this scenario as well), instead of the raw ribbon method.
I had to do one fix in the ribbon converter as well. It required at least two cells in the polydata, but I don’t know why so I decreased it to one (@lassoan any ideas?) and now it works well. You’ll be able to try it with tomorrow’s nightly. Also you’ll need to disable the direct conversion that @Sunderlandkyl is fixing now. You can do it by entering this in the python interactor before loading the data, or adding this to .slicerrc.py. However this is a temporary workaround in case you’re in a rush.
f=slicer.vtkSegmentationConverterFactory()
f.DisableConverterRule('Planar contour', 'Closed surface')
It will look like this:
