code: def xz_align_matrix(self):
      # no transformation is required in 3D tool,
      # just return a identity matrix here
      transM = np.identity(4)
      m = [x for y in transM for x in y]
      mat = vtk.vtkMatrix4x4()
      mat.DeepCopy(m)
      mat.Transpose()
      return mat
  
imports: import vtk
  import json
  import numpy
  import argparse
  import sys
  import subprocess
  from plyfile import PlyData
label_desc: Use image node_id 15 for calling the Render obj's underlying member method code with example usage: obj.xz_align_matrix() and returns: mat