plane.py 文件源码

def from_points(cls, p1, p2, p3):
        '''
        If the points are oriented in a counterclockwise direction, the plane's
        normal extends towards you.

        '''
        from blmath.numerics import as_numeric_array

        p1 = as_numeric_array(p1, shape=(3,))
        p2 = as_numeric_array(p2, shape=(3,))
        p3 = as_numeric_array(p3, shape=(3,))

        v1 = p2 - p1
        v2 = p3 - p1
        normal = np.cross(v1, v2)

        return cls(point_on_plane=p1, unit_normal=normal)