Understanding Differentiable Volumetric Rendering
In this chapter, we are going to discuss a new way of differentiable rendering. We are going to use a voxel 3D data representation, unlike the mesh 3D data representation we used in the last chapter. Voxel 3D data representation has certain advantages compared to mesh models. For example, it is more flexible and highly structured.
To understand volumetric rendering, we need to understand several important concepts, such as ray sampling, volumes, volume sampling, and ray marching. All these concepts have corresponding PyTorch3D implementations. We will discuss each of these concepts using explanations and coding exercises.
After we understand the preceding basic concepts of volumetric rendering, we can then see easily that all the operations mentioned already are already differentiable. Volumetric rendering is naturally differentiable. Thus, by then, we will be ready to use differentiable volumetric rendering for some real applications...
