Hmm, that would be a bit tougher to deal with. Specifically as the slice approaches 100% full, how should the outline behave?
One way would be for the yellow wedge to progressively “bite” into the black line until it disappears, but achieving that effect would be a bit tricky since we are faking the wedge outlines on Synfig. I have some ideas on how try to achieve that but it would take a diferent more complex approach.
This one is like 50% of the way there:
piechart-2.sif (9.61 KB)
The tough part is removing the extra black leaving only the thin outline.