Can you clarify what you mean by Procedural Generator? Isn't a generative model already a procedural generator? Its just that a model generated in case of the referred paper is voxel based. Did you mean, generate parameters of a pre-specified model e.g https://graphics.ethz.ch/~edibra/Publications/HS-Nets%20-%20... , although this paper is just learning a regression to the human body model (not using GANs).
Curious to know more about your train of thought. I am working as a researcher in the domain and thinking of experimenting with GANs for 3D model estimation using similar inputs as the one in the paper I referred to.
Well, not exact cause I don't like their voxel building generation method.
I think a GAN + Procedural Generator is the winner.
edit: Let me know if you want to work on this cause it's an active area of research for us. See my HN profile for contact.