It would be nice if RhinoCommon supported the calculation of
AreaMassProperties for multiple curves, similar to the way that the AreaMoments command works on multiple curves.
I have - for now - created a native implementation using
ON_MassProperties with a few dirty hacks to get it into RhinoCommon. I think it would be better if is supported out-of-the-box.
A few things I noticed: the AreaMoments command does not detect/support counter-clockwise curves, and it would be nice - at least in code - to be able to have nested curves with opposite planar orientations to add/subtract area and mass. Furthermore, the command does not notice that the curves are not in the same plane, and I think that calculation of the moments only makes sense if the curves are all in the same plane.
If you want I can share my native-to-.NET implementation.