Spatially-Adaptive Hash Encodings for Neural Surface Reconstruction

Thomas Walker, Octave Mariotti, Amir Vaxman, Hakan Bilen; Proceedings of the Winter Conference on Applications of Computer Vision (WACV), 2025, pp. 2963-2972

Positional encodings are a common component of neural scene reconstruction methods and provide a way to bias the learning of neural fields towards coarser or finer representations. Current neural surface reconstruction methods use a "one-size-fits-all" approach to encoding choosing a fixed set of encoding functions and therefore bias across all scenes. Current state-of-the-art surface reconstruction approaches leverage grid-based multi-resolution hash encoding in order to recover high-detail geometry. We propose a learned approach which allows the network to choose its encoding basis as a function of space by masking the contribution of features stored at separate grid resolutions. The resulting spatially adaptive approach allows the network to fit a wider range of frequencies without introducing noise. We test our approach on standard benchmark surface reconstruction datasets and achieve state-of-the-art performance on two benchmark datasets.