docstr: :param ply_file: path of ply file
  :param json_file: path of annotation result json file
  :param back_face_cull: see single side of mesh
code: def __init__(self, ply_file, json_file, back_face_cull=False):
      """
      :param ply_file: path of ply file
      :param json_file: path of annotation result json file
      :param back_face_cull: see single side of mesh
      """
      self.annotation = load_json(json_file)
      self.file = ply_file
      self.back_face_cull = back_face_cull
      self.reader = vtk.vtkPLYReader()
      self.colors = vtk.vtkNamedColors()
      self.mapper = vtk.vtkPolyDataMapper()
      self.actor = vtk.vtkActor()
      self.ren = vtk.vtkRenderer()
      self.renWin = vtk.vtkRenderWindow()
      self.iren = vtk.vtkRenderWindowInteractor()
      self.offset_x, self.offset_y, self.offset_z = 0, 0, 0
      self.vertex = []
      self.file_type = None
  
imports: import vtk
  import json
  import numpy
  import argparse
  import sys
  import subprocess
  from plyfile import PlyData
label_desc: Use image node_id 1 to create a new Render object from inherited base classes: object with example: obj = Render(ply_file, json_file, back_face_cull)