code: def test_compare_rasterizers(self):
      device = torch.device("cuda:0")
  
      # Init rasterizer settings
      R, T = look_at_view_transform(2.7, 0, 0)
      cameras = FoVPerspectiveCameras(device=device, R=R, T=T)
      raster_settings = RasterizationSettings(
          image_size=512,
          blur_radius=0.0,
          faces_per_pixel=1,
          bin_size=0,
          perspective_correct=True,
      )
      from pytorch3d.io import load_obj
      from pytorch3d.renderer import TexturesAtlas
  
      from .common_testing import get_pytorch3d_dir
  
      TUTORIAL_DATA_DIR = get_pytorch3d_dir() / "docs/tutorials/data"
      obj_filename = TUTORIAL_DATA_DIR / "cow_mesh/cow.obj"
  
      # Load mesh and texture as a per face texture atlas.
      verts, faces, aux = load_obj(
          obj_filename,
          device=device,
          load_textures=True,
          create_texture_atlas=True,
          texture_atlas_size=8,
          texture_wrap=None,
      )
      atlas = aux.texture_atlas
      mesh = Meshes(
          verts=[verts],
          faces=[faces.verts_idx],
          textures=TexturesAtlas(atlas=[atlas]),
      )
  
      # Rasterize using both rasterizers and compare results.
      rasterizer = MeshRasterizerOpenGL(
          cameras=cameras, raster_settings=raster_settings
      )
      fragments_opengl = rasterizer(mesh)
  
      rasterizer = MeshRasterizer(
          cameras=cameras, raster_settings=raster_settings
      )
      fragments = rasterizer(mesh)
  
      # Ensure that 99.9% of bary_coords is at most 0.001 different.
      self.assertLess(
          torch.quantile(
              (
                  fragments.bary_coords - fragments_opengl.bary_coords
              ).abs(),
              0.999,
          ),
          0.001,
      )
  
      # Ensure that 99.9% of zbuf vals is at most 0.001 different.
      self.assertLess(
          torch.quantile(
              (fragments.zbuf - fragments_opengl.zbuf).abs(), 0.999
          ),
          0.001,
      )
  
      # Ensure that 99.99% of pix_to_face is identical.
      self.assertEqual(
          torch.quantile(
              (
                  fragments.pix_to_face != fragments_opengl.pix_to_face
              ).float(),
              0.9999,
          ),
          0,
      )
  
imports: import unittest
  import numpy
  import torch
  from PIL import Image
  from pytorch3d.renderer import FoVOrthographicCameras, FoVPerspectiveCameras, look_at_view_transform, MeshRasterizer, OrthographicCameras, PerspectiveCameras, PointsRasterizationSettings, PointsRasterizer, RasterizationSettings
  from pytorch3d.renderer.fisheyecameras import FishEyeCameras
  from pytorch3d.renderer.opengl.rasterizer_opengl import _check_cameras, _check_raster_settings, _convert_meshes_to_gl_ndc, _parse_and_verify_image_size, MeshRasterizerOpenGL
  from pytorch3d.structures import Pointclouds
  from pytorch3d.structures.meshes import Meshes
  from pytorch3d.utils.ico_sphere import ico_sphere
  from .common_testing import get_tests_dir, TestCaseMixin
label_desc: Use image node_id 7 for calling the TestMeshRasterizer obj's underlying member method code with example usage: obj.test_compare_rasterizers() without return types