Traditional NeRFs face limitations in 3D reconstruction, as they are inherently limited to forward rendering tasks and cannot invert to deduce the 3D structure from 2D projections. This hinders their broader applicability in real-world scenarios requiring accurate 3D representations from limited viewpoints, such as augmented reality, virtual reality, and robotic perception.
The new 3D reconstruction method introduced by the researchers leverages a learned feature space and an optimization framework to invert NeRFs. The key elements of this approach include a feature encoder that maps input images to a latent space, a differentiable rendering process that synthesizes 2D views from the latent representation, and a latent code that captures the underlying 3D structure of the scene. This innovative method enables the reconstruction of 3D scenes from a sparse set of 2D images.
Current 3D scene reconstruction methods face challenges when handling sparse data. Multi-view stereo techniques require numerous images, making them impractical for real-time applications. Voxel-based approaches suffer from high memory consumption and computational demands, while mesh-based methods often lack the ability to capture fine details accurately. These limitations hinder the performance and applicability of existing methods, particularly in scenarios with limited or sparse input data.