The Path class provides methods for querying, creating, and modifying SV  
path planning objects.                                                    

add_control_point(point, index=None) 
   
   Add a control point to a path. 
   
   The point is inserted into the path's list of control points at the location to the control point it is closest to.  
   If the 'location' argument is given then the point is added at that location in the list. 
   
   Args: 
     point (list[float,float,float]): The control point (x,y,z) coordinates. 
     index (Optional[int]): The index into the current list of control points to add the control point. 0 <= index <= number of path control points - 1

get_control_points() 
   
   Get the path's control points. 
   
   Returns (list(list[float,float,float])): The list of the path's control points. 

get_curve_frame(index) 
   
   Get the coordinate frame at the path's interpolating curve at a given location. 
   
   Args: 
     index (int): The index into the path's curve frames. 0 <= index <= number of path curve frames - 1. 
   
   Returns (list([float,float,float])): The path's curve normal at the given location. 

get_curve_normal(index) 
   
   Get the normal to the path's interpolating curve at a given location. 
   
   Args: 
     index (int): The index into the path's curve normals. 0 <= index <= number of path curve points - 1. 
   
   Returns (list([float,float,float])): The path's curve normal at the given location. 

get_curve_point(index) 
   
   Get the point on the path's interpolating curve at a given location. 
   
   Args: 
     index (int): The index into the path's curve points. 0 <= index <= number of path curve points - 1. 
   
   Returns (list([float,float,float])): The path's curve point at the given location. 

get_curve_points() 
   
   Get the points along the path's interpolating curve. 
   
   Returns (list(list[float,float,float])): The list of the path's interpolating curve points. 

get_curve_polydata() 
   
   Get the vtkPolyData object representing the path's interpolating curve. 
   
   Returns (vtkPolyData): The vtkPolyData object representing the path's interpolating curve.  

get_curve_tangent(index) 
   
   Get the tangent to the path's interpolating curve at a given location. 
   
   Args: 
     index (int): The index into the path's curve tangents. 0 <= index <= number of path curve tangents - 1. 
   
   Returns (list([float,float,float])): The path's curve tangent at the given location. 

get_num_curve_points() 
   
   Get the number of points along the path's interpolating curve. 
   
   Returns (int): The number of points along the path's interpolating curve. 

get_num_subdivisions() 
   
   Get the path group's calculation number. 
   
   Returns (int): The path group's calculation number. 

get_subdivision_method() 
   
   Get the path's subdivision method. 
   
   Returns (str): The path's subdivsion method. 

get_subdivision_spacing() 
   
   Get the path's subdivsion spacing value. 
   
   Returns (float): The path's subdivsion spacling value. 

remove_control_point(index) 
   
   Remove a control point from a path. 
   
   Args: 
     index (int): The index into the path's list of control points of the control point to remove. 0 <= index <= number of control points - 1. 

replace_control_point(index, point) 
   
   Replace a control point in a path. 
   
   Args: 
     index (int): The index into the path's list of control points of the control point to remove. 0 <= index <= number of control points - 1. 
     point (list[float,float,float]): A list of three floats represent the coordinates of a 3D point. 

set_control_points(points) 
   
   Set the path's control points. 
   
   Args: 
     points (list(list[float,float,float])): The list of control points. 

set_subdivision_method(method, num_subdiv=None, num_total=None, spacing=None) 
   
   Set the subdivision method and paramters used to determine the number of path curve points created between two adjacent control points. 
   
   The optional parameters are only used with the appropriate method being set. The path's curve points are updated using the given 
   method and paramater value. 
   
   Args: 
     method (str): The subdivision method name. Valid names are: SPACING, SUBDIVISION or TOTAL 
     num_div (Optional[int]): The number of subdivisions used with the SUBDIVISION method. 
     num_total (Optional[int]): The number of total subdivisions used with the TOTAL method. 
     spacing (Optional[float]): The spacing by the SPACING method. 

smooth(sample_rate, num_modes, smooth_control_pts=False) 
   
   Smooth a path's control points or curve points as a source. 
   
   Args: 
     sample_rate (int): The rate used to sample the source points for smoothing. 
        A sample rate of 2 uses every other point for smoothing. 
     num_modes (int): The number of Fourier modes used to reconstuct the source points. 
        The lower the number of modes the more the source points are smoothed. 
     control_point_based (Optional[bool]): If True then smooth control points; otherwise smooth curve points. 
   
   Returns (sv.path.Path object): A new smoothed path.