Framework of the proposed NIM for small body shape modeling. The network employs an MLP architecture to learn neural fields that encode the SDF and color information, using volumetric rendering to integrate these properties and ultimately reconstruct the target shape models (Sect. 2.1). This method relies on a limited number of images while leveraging multi-scale deformation grids (Sect. 2.2) and explicit SDF constraints (Sect. 2.3) to reconstruct high-resolution shape models.