def normal_array(self, us, vs):
numerator, denominator = self.fraction(0, 0, us, vs)
surface = nurbs_divide(numerator, denominator)
numerator_u, denominator_u = self.fraction(1, 0, us, vs)
numerator_v, denominator_v = self.fraction(0, 1, us, vs)
surface_u = nurbs_divide(numerator_u - surface * denominator_u,
denominator)
surface_v = nurbs_divide(numerator_v - surface * denominator_v,
denominator)
normal = np.cross(surface_u, surface_v)
n = np.linalg.norm(normal, axis=1, keepdims=True)
normal = nurbs_divide(normal, n)
return normal
def derivatives_data_array(self, us, vs):
numerator, denominator = self.fraction(0, 0, us, vs)
surface = nurbs_divide(numerator, denominator)
numerator_u, denominator_u = self.fraction(1, 0, us, vs)
numerator_v, denominator_v = self.fraction(0, 1, us, vs)
surface_u = (numerator_u - surface * denominator_u) / denominator
surface_v = (numerator_v - surface * denominator_v) / denominator
return SurfaceDerivativesData(surface, surface_u, surface_v)
def curvature_calculator(self, us, vs, order=True):
numerator, denominator = self.fraction(0, 0, us, vs)
surface = nurbs_divide(numerator, denominator)
numerator_u, denominator_u = self.fraction(1, 0, us, vs)
numerator_v, denominator_v = self.fraction(0, 1, us, vs)
surface_u = (numerator_u - surface * denominator_u) / denominator
surface_v = (numerator_v - surface * denominator_v) / denominator
normal = np.cross(surface_u, surface_v)
n = np.linalg.norm(normal, axis=1, keepdims=True)
normal = normal / n
numerator_uu, denominator_uu = self.fraction(2, 0, us, vs)
surface_uu = (numerator_uu - 2 * surface_u * denominator_u -
surface * denominator_uu) / denominator
numerator_vv, denominator_vv = self.fraction(0, 2, us, vs)
surface_vv = (numerator_vv - 2 * surface_v * denominator_v -
surface * denominator_vv) / denominator
numerator_uv, denominator_uv = self.fraction(1, 1, us, vs)
surface_uv = (numerator_uv - surface_v * denominator_u - surface_u *
denominator_v - surface * denominator_uv) / denominator
nuu = (surface_uu * normal).sum(axis=1)
nvv = (surface_vv * normal).sum(axis=1)
nuv = (surface_uv * normal).sum(axis=1)
duu = np.linalg.norm(surface_u, axis=1)**2
dvv = np.linalg.norm(surface_v, axis=1)**2
duv = (surface_u * surface_v).sum(axis=1)
calc = SurfaceCurvatureCalculator(us, vs, order=order)
calc.set(surface, normal, surface_u, surface_v, duu, dvv, duv, nuu,
nvv, nuv)
return calc
def evaluate_array(self, ts):
numerator, denominator = self.fraction(0, ts)
# if (denominator == 0).any():
# print("Num:", numerator)
# print("Denom:", denominator)
return nurbs_divide(numerator, denominator)
def evaluate_array(self, us, vs):
numerator, denominator = self.fraction(0, 0, us, vs)
return nurbs_divide(numerator, denominator)
