Hello Alexey,
in this case, please see my post as a feature request!
Maybe you want to remove parking cars, trees and bushes or some containers, before calculating the volume. If i do this with a mesh, i have to create one first, then delete all the unwanted objects and in the last step, i have to close the holes again, before being able to calculate the volume.
Using vector shapes, this would be much easier and faster!
Best regards
Thomas