Computes the volume of 3D elements in a vectorized manner Currently only hexahedrals are supported.
Version : 1.0
Author : George Kourakos
Department of Land Air and Water
University of California Davis
p : [Np x 3] coordinates
MSH : [Nel, Nsh] Mesh element ids. Nel is the number of elements and Nsh is the number of shapefunctions. The ids correspond to the row of the array p
V : [Nel x 1] The volume of each element