How it is coded

The code is provided in the repository in the chap4 folder as diff_render.py. The mesh model of the teapot is provided in the data subfolder as teapot.obj. We will run through the code as follows:

1. The code in diff_render.py starts by importing the needed packages:

   import os
   import torch
   import numpy as np
   import torch.nn as nn
   import matplotlib.pyplot as plt
   from skimage import img_as_ubyte
   from pytorch3d.io import load_obj
   from pytorch3d.structures import Meshes
   from pytorch3d.renderer import (
   FoVPerspectiveCameras, look_at_view_transform, look_at_rotation,
   RasterizationSettings, MeshRenderer, MeshRasterizer, BlendParams,
   SoftSilhouetteShader, HardPhongShader, PointLights, TexturesVertex,
   )

2. In the next step, we declare a PyTorch device. If you have GPUs, then the device will be created to use GPUs. Otherwise, the device has to use CPUs:

   if torch.cuda.is_available():
       device = torch.device("cuda:0")
   else:
      ...