docstr: End-End debug run of rendering a cube mesh with texture
  from decreasing camera distances. The camera starts
  outside the cube and enters the inside of the cube.
docstr_tok: ["End-End","debug","run","of","rendering","a","cube","mesh","with","texture","from","decreasing","camera","distances",".","The","camera","starts","outside","the","cube","and","enters","the","inside","of","the","cube","."]
code: def debug_cube_mesh_render(self):
      """
      End-End debug run of rendering a cube mesh with texture
      from decreasing camera distances. The camera starts
      outside the cube and enters the inside of the cube.
      """
      device = torch.device("cuda:0")
      mesh = self.load_cube_mesh_with_texture(device)
      raster_settings = RasterizationSettings(
          image_size=512,
          blur_radius=1e-8,
          faces_per_pixel=5,
          z_clip_value=1e-2,
          perspective_correct=True,
          bin_size=0,
      )
  
      # Only ambient, no diffuse or specular
      lights = PointLights(
          device=device,
          ambient_color=((1.0, 1.0, 1.0),),
          diffuse_color=((0.0, 0.0, 0.0),),
          specular_color=((0.0, 0.0, 0.0),),
          location=[[0.0, 0.0, -3.0]],
      )
  
      renderer = MeshRenderer(
          rasterizer=MeshRasterizer(raster_settings=raster_settings),
          shader=SoftPhongShader(device=device, lights=lights),
      )
  
      # Render the cube by decreasing the distance from the camera until
      # the camera enters the cube. Check the output looks correct.
      images_list = []
      dists = np.linspace(0.1, 2.5, 20)[::-1]
  
      for d in dists:
          R, T = look_at_view_transform(d, 0, 0)
          T[0, 1] -= 0.1  # move down in the y axis
          cameras = FoVPerspectiveCameras(
              device=device, R=R, T=T, fov=90
          )
          images = renderer(mesh, cameras=cameras)
          rgb = images[0, ..., :3].cpu().detach()
          im = (rgb.numpy() * 255).astype(np.uint8)
          images_list.append(im)
  
      # Save a gif of the output - this should show
      # the camera moving inside the cube.
      if DEBUG:
          gif_filename = (
              "room_original.gif"
              if raster_settings.z_clip_value is None
              else "room_clipped.gif"
          )
          imageio.mimsave(DATA_DIR / gif_filename, images_list, fps=2)
          save_obj(
              f=DATA_DIR / "cube.obj",
              verts=mesh.verts_packed().cpu(),
              faces=mesh.faces_packed().cpu(),
          )
  
imports: import unittest
  import imageio
  import numpy
  import torch
  from pytorch3d.io import save_obj
  from pytorch3d.renderer.cameras import FoVPerspectiveCameras, look_at_view_transform, PerspectiveCameras
  from pytorch3d.renderer.lighting import PointLights
  from pytorch3d.renderer.mesh import clip_faces, ClipFrustum, convert_clipped_rasterization_to_original_faces, TexturesUV
  from pytorch3d.renderer.mesh.rasterize_meshes import _RasterizeFaceVerts
  from pytorch3d.renderer.mesh.rasterizer import MeshRasterizer, RasterizationSettings
  from pytorch3d.renderer.mesh.renderer import MeshRenderer
  from pytorch3d.renderer.mesh.shader import SoftPhongShader
  from pytorch3d.renderer.mesh.textures import TexturesVertex
  from pytorch3d.structures.meshes import Meshes
  from pytorch3d.utils import torus
  from .common_testing import get_tests_dir, load_rgb_image, TestCaseMixin
label_desc: Use image node_id 2 for calling the TestRenderMeshesClipping obj's underlying member method code with example usage: obj.debug_cube_mesh_render() without return types