def frame_at(self, u, v):
"""Compute the local frame at a point on the curve.
Parameters
----------
u : float
v : float
Returns
-------
:class:`~compas.geometry.Frame`
"""
point = gp_Pnt()
uvec = gp_Vec()
vvec = gp_Vec()
self.occ_surface.D1(u, v, point, uvec, vvec)
return Frame(Point.from_occ(point), Vector.from_occ(uvec),
Vector.from_occ(vvec))
def curvature_at(self, u, v):
"""Compute the curvature at a point on the surface.
Parameters
----------
u : float
v : float
Returns
-------
:class:`~compas.geometry.Vector`
"""
props = GeomLProp_SLProps(self.occ_surface, u, v, 2, 1e-6)
gaussian = props.GaussianCurvature()
mean = props.MeanCurvature()
point = props.Value()
normal = props.Normal()
return gaussian, mean, Point.from_occ(point), Vector.from_occ(normal)