class ShapeProps(object):
"""
Base class for shape properties.
"""
def __init__(self):
self._props = GProp_GProps()
@property
def mass(self):
"""
:return: The mass of the shape. This corresponds to total length for
linear properties, total area for surface properties, or total
volume for volume properties.
:rtype: float
"""
return self._props.Mass()
@property
def cg(self):
"""
:return: The center of gravity.
:rtype: afem.geometry.entities.Point
"""
gp_pnt = self._props.CentreOfMass()
return Point(gp_pnt.X(), gp_pnt.Y(), gp_pnt.Z())
@property
def static_moments(self):
"""
:return: The static moments of inertia Ix, Iy, and Iz.
:rtype: tuple(float)
"""
return self._props.StaticMoments(0., 0., 0.)
@property
def matrix_of_inertia(self):
"""
:return: The 3 x 3 matrix of inertia.
:rtype: numpy.ndarray
"""
gp_mat = self._props.MatrixOfInertia()
matrix = []
for j in range(1, 4):
row = []
for i in range(1, 4):
row.append(gp_mat.Value(i, j))
matrix.append(row)
return array(matrix, dtype=float)
def moment_of_inertia(self, axis):
"""
Compute the moment of inertia about the axis.
:param afem.geometry.entities.Axis1 axis: The axis.
:return: The moment of inertia.
:rtype: float
"""
return self._props.MomentOfInertia(axis)
class PropsBase(object):
"""
Base class for shape properties.
"""
def __init__(self):
self._props = GProp_GProps()
@property
def mass(self):
"""
:return: The mass of the shape. This corresponds to total length for
linear properties, total area for surface properties, or total
volume for volume properties.
:rtype: float
"""
return self._props.Mass()
@property
def cg(self):
"""
:return: The center of gravity.
:rtype: OCCT.gp.gp_Pnt
"""
return self._props.CentreOfMass()
@property
def static_moments(self):
"""
:return: The static moments of inertia Ix, Iy, and Iz.
:rtype: tuple(float)
"""
return self._props.StaticMoments(0., 0., 0.)
def moment_of_inertia(self, axis):
"""
Compute the moment of inertia about the axis.
:param OCCT.gp.gp_Ax1 axis: The axis.
:return: The moment of inertia.
:rtype: float
"""
return self._props.MomentOfInertia(axis)