Voxels are directly analogous to 2d pixels, which means they benefit from the myriad of CNN based techniques developed over the last few years (GAN in particula

Voxels are directly analogous to 2d pixels, which means they benefit from the myriad of CNN based techniques developed over the last few years (GAN in particular) 3d manifolds are sparse, and more analogous to 2d vector graphics. There are approaches for dealing with this type of data (eg. spectral graph NN) but they don't work as well for 3d topology as CNNs do for dense pixel data, as far as I know. In the near term, it might be better to explore approaches that use voxels, then generate the topology heuristically.