code: def test_synthetic(self):
      if inside_re_worker:
          return
      expand_args_fields(BlenderDatasetMapProvider)
  
      provider = BlenderDatasetMapProvider(
          base_dir="manifold://co3d/tree/nerf_data/nerf_synthetic/lego",
          object_name="lego",
      )
      dataset_map = provider.get_dataset_map()
      known_matrix = torch.zeros(1, 4, 4)
      known_matrix[0, 0, 0] = 2.7778
      known_matrix[0, 1, 1] = 2.7778
      known_matrix[0, 2, 3] = 1
      known_matrix[0, 3, 2] = 1
  
      for name, length in [("train", 100), ("val", 100), ("test", 200)]:
          dataset = getattr(dataset_map, name)
          self.assertEqual(len(dataset), length)
          # try getting a value
          value = dataset[0]
          self.assertEqual(value.image_rgb.shape, (3, 800, 800))
          self.assertEqual(value.fg_probability.shape, (1, 800, 800))
          # corner of image is background
          self.assertEqual(value.fg_probability[0, 0, 0], 0)
          self.assertEqual(value.fg_probability.max(), 1.0)
          self.assertIsInstance(value.camera, PerspectiveCameras)
          self.assertEqual(len(value.camera), 1)
          self.assertIsNone(value.camera.K)
          matrix = value.camera.get_projection_transform().get_matrix()
          self.assertClose(matrix, known_matrix, atol=1e-4)
          self.assertIsInstance(value, FrameData)
  
file_path: pytorch3d/tests/implicitron/test_data_llff.py
imports: import os
  import unittest
  import torch
  from pytorch3d.implicitron.dataset.blender_dataset_map_provider import BlenderDatasetMapProvider
  from pytorch3d.implicitron.dataset.data_source import ImplicitronDataSource
  from pytorch3d.implicitron.dataset.dataset_base import FrameData
  from pytorch3d.implicitron.dataset.llff_dataset_map_provider import LlffDatasetMapProvider
  from pytorch3d.implicitron.tools.config import expand_args_fields, get_default_args
  from pytorch3d.renderer import PerspectiveCameras
  from tests.common_testing import TestCaseMixin
label_desc: Use image node_id 1 for calling the TestDataLlff obj's underlying member method code with example usage: obj.test_synthetic() without return types