Standalone Pulsar renderer

Pulsar is an early differentiable 3D renderer. It has been part of PyTorch 3D for a long time. I used it for a CLIP-guided 3D shape generation project in summer 2022.

Pulsar is difficult to install because it only comes shipped with PyTorch 3D. The recommended methods for installing PyTorch 3D are, in order:

1. Using pip wheels... For torch 1.x
2. Installing a conda package
3. Compiling from source Each of those has self-evident flaws. The installation process does not need to be this way if one only wants to use Pulsar: the renderer is just a few CUDA files and self-contained C++ bindings.

I extracted the source files for Pulsar from PyTorch 3D and set up a build process for them. The result is a pip installable git repo: git+github.com/neverix/pulsar.