docstr: Case 2 triangles are fully behind the image plane (z=0) so are completely culled.
  Test with a single triangle behind the image plane.
docstr_tok: ["Case","2","triangles","are","fully","behind","the","image","plane","(","z=0",")","so","are","completely","culled",".","Test","with","a","single","triangle","behind","the","image","plane","."]
code: def test_case_2(self):
      """
      Case 2 triangles are fully behind the image plane (z=0) so are completely culled.
      Test with a single triangle behind the image plane.
      """
  
      device = "cuda:0"
      verts = torch.tensor(
          [[-1.0, 0.0, -1.0], [0.0, 1.0, -1.0], [1.0, 0.0, -1.0]],
          dtype=torch.float32,
          device=device,
      )
      faces = torch.tensor(
          [
              [0, 1, 2],
          ],
          dtype=torch.int64,
          device=device,
      )
      meshes = Meshes(verts=[verts], faces=[faces])
      clipped_faces = self.clip_faces(meshes)
  
      zero_t = torch.zeros(size=(1,), dtype=torch.int64, device=device)
      self.assertClose(
          clipped_faces.face_verts,
          torch.empty(device=device, size=(0, 3, 3)),
      )
      self.assertClose(clipped_faces.mesh_to_face_first_idx, zero_t)
      self.assertClose(clipped_faces.num_faces_per_mesh, zero_t)
      self.assertClose(
          clipped_faces.faces_clipped_to_unclipped_idx,
          torch.empty(device=device, dtype=torch.int64, size=(0,)),
      )
      self.assertIsNone(clipped_faces.faces_clipped_to_conversion_idx)
      self.assertIsNone(clipped_faces.clipped_faces_neighbor_idx)
      self.assertIsNone(clipped_faces.barycentric_conversion)
  
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 6 for calling the TestRenderMeshesClipping obj's underlying member method code with example usage: obj.test_case_2() without return types