  We investigate the use of Neural Radiance Fields (NeRF) to learn high quality
3D object category models from collections of input images. In contrast to
previous work, we are able to do this whilst simultaneously separating
foreground objects from their varying backgrounds. We achieve this via a
2-component NeRF model, FiG-NeRF, that prefers explanation of the scene as a
geometrically constant background and a deformable foreground that represents
the object category. We show that this method can learn accurate 3D object
category models using only photometric supervision and casually captured images
of the objects. Additionally, our 2-part decomposition allows the model to
perform accurate and crisp amodal segmentation. We quantitatively evaluate our
method with view synthesis and image fidelity metrics, using synthetic,
lab-captured, and in-the-wild data. Our results demonstrate convincing 3D
object category modelling that exceed the performance of existing methods.
