def pltvol(vrtces, plates):
    """
    Compute the volume of a three-dimensional region bounded by a 
    collection of triangular plates. 
    
    https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/pltvol_c.html
 
    :param vrtces: Array of vertices.
    :type vrtces: Nx3-Element Array of floats
    :param plates: Array of plates. 
    :type plates: Nx3-Element Array of ints 
    :return: the volume of the spatial region bounded by the plates. 
    :rtype: float
    """
    nv = ctypes.c_int(len(vrtces))
    vrtces = stypes.toDoubleMatrix(vrtces)
    np = ctypes.c_int(len(plates))
    plates = stypes.toIntMatrix(plates)
    return libspice.pltvol_c(nv, vrtces, np, plates)