code: def random_model3d():
      model_3d = random.choice(
          [
              os.path.join(model3d_dir, model)
              for model in os.listdir(model3d_dir)
              if model != "source.txt"
          ]
      )
      return model_3d
  
imports: import numpy
  import matplotlib.pyplot
  import random
  import os
label_desc: Use image node_id 2 for calling a global function with example usage: random_model3d() and returns: model_3d