CAMPARI: Camera-Aware Decomposed Generative Neural Radiance Fields
Michael Niemeyer and Andreas Geiger
Tremendous progress in deep generative models has led to photorealistic image synthesis. While achieving compelling results, most approaches operate in the two-dimensional image domain, ignoring the three-dimensional nature of our world. Several recent works therefore propose generative models which are 3D-aware, i.e., scenes are modeled in 3D and then rendered differentiably to the image plane. While this leads to impressive 3D~consistency, the camera needs to be modelled as well and we show in this work that these methods are sensitive to the choice of prior camera distributions. Current approaches assume fixed intrinsics and predefined priors over camera pose ranges, and parameter tuning is typically required for real-world data. If the data distribution is not matched, results degrade significantly. Our key hypothesis is that learning a camera generator jointly with the image generator leads to a more principled approach to 3D-aware image synthesis. Further, we propose to decompose the scene into a background and foreground model, leading to more efficient and disentangled scene representations. While training from raw, unposed image collections, we learn a 3D- and camera-aware generative model which faithfully recovers not only the image but also the camera data distribution. At test time, our model generates images with explicit control over the camera as well as the shape and appearance of the scene.