Meaning of Mesh_volume in filter get_geometric_measures()

[jabruniessner]

Hey there,

So the filter ms.get_geometric_measures() return a dictionary containing several key, amongst which:

"mesh_volume "

Just now I was analyzing a mesh and had a negative value for this key. That raises the question, what is the meaning of this number?
And what is the meaning of the volume. For a watertight mesh it makes intuitive sense, but if the mesh is not water tight, what does it mean?

If anyone has an idea, thanks in advance!