INFAMOUS-NeRF: ImproviNg FAce MOdeling Using Semantically-Aligned
  Hypernetworks with Neural Radiance Fields
Andrew Hou Feng Liu Zhiyuan Ren Michel Sarkis Ning Bi Yiying Tong Xiaoming Liu
We propose INFAMOUS-NeRF, an implicit morphable face model that introduces
hypernetworks to NeRF to improve the representation power in the presence of
many training subjects. At the same time, INFAMOUS-NeRF resolves the classic
hypernetwork tradeoff of representation power and editability by learning
semantically-aligned latent spaces despite the subject-specific models, all
without requiring a large pretrained model. INFAMOUS-NeRF further introduces a
novel constraint to improve NeRF rendering along the face boundary. Our
constraint can leverage photometric surface rendering and multi-view
supervision to guide surface color prediction and improve rendering near the
surface. Finally, we introduce a novel, loss-guided adaptive sampling method
for more effective NeRF training by reducing the sampling redundancy. We show
quantitatively and qualitatively that our method achieves higher representation
power than prior face modeling methods in both controlled and in-the-wild
settings. Code and models will be released upon publication.