def normal_to_face_center(face):
u_min, u_max, v_min, v_max = breptools_UVBounds(face)
u_mid = (u_min + u_max) / 2.
v_mid = (v_min + v_max) / 2.
surf = BRep_Tool_Surface(face)
normal = GeomLProp_SLProps(surf,u_mid, v_mid,1,0.01).Normal()
if face.Orientation() == TopAbs_REVERSED:
normal.Reverse()
return normal
def sample_point(face):
# randomly choose a point from F
u_min, u_max, v_min, v_max = breptools_UVBounds(face)
u = random.uniform(u_min, u_max)
v = random.uniform(v_min, v_max)
itool = IntTools_FClass2d(face, 1e-6)
while itool.Perform(gp_Pnt2d(u,v)) != 0:
print('outside')
u = random.uniform(u_min, u_max)
v = random.uniform(v_min, v_max)
P = BRepAdaptor_Surface(face).Value(u, v)
# the normal
surf = BRep_Tool_Surface(face)
D = GeomLProp_SLProps(surf,u,v,1,0.01).Normal()
if face.Orientation() == TopAbs_REVERSED:
D.Reverse()
return P, D