A part of a section, in the coordinates of the part it was cut from: its id, its kind, its
shape and its shapeHash, the same for the same part and the same plane through it in every
section, so a drawer keeps one mesh for it. It keeps the cut part's colour and finish, without
the colours of single faces and edges. A cap gives its area, a piece or a whole part its volume
when it is solid.
A part of a section, in the coordinates of the part it was cut
from: itsid, itskind, itsshapeand itsshapeHash, the same for the same part and the same plane through it in every section, so a drawer keeps one mesh for it. It keeps the cut part's colour and finish, without the colours of single faces and edges. A cap gives itsarea, a piece or a whole part itsvolumewhen it is solid.