Neural shape models can represent complex 3D shapes with a compact latent space. When applied to dynamically deforming shapes such as the human hands, however, they would need to preserve temporal coherence of the deformation as well as the intrinsic identity of the subject. These properties are difficult to regularize with manually designed loss functions. In this paper, we learn a neural deformation model that disentangles the identity-induced shape variations from pose-dependent deformations using implicit neural functions. We perform template-free unsupervised learning on 3D scans without explicit mesh correspondence or semantic correspondences of shapes across subjects. We can then apply the learned model to reconstruct partial dynamic 4D scans of novel subjects performing unseen actions. We propose two methods to integrate global pose alignment with our neural deformation model. Experiments demonstrate the efficacy of our method in the disentanglement of identities and pose. Our method also outperforms traditional skeleton-driven models in reconstructing surface details such as palm prints or tendons without limitations from a fixed template.
翻译:神经形状模型可以代表复杂的 3D 形状, 具有紧凑的潜伏空间。 但是, 当应用到动态变形形状, 如人体手等时, 它们需要保存变形的时间一致性以及主题的内在特性。 这些特性很难与人工设计的丢失功能正规化 。 在本文中, 我们学习了一种神经变形模型, 通过隐含的神经功能, 将身份诱发的形状变异分解分解开来 。 我们在3D 扫描上进行无模板且不受监督的学习, 没有清晰的网状对应或各学科形状的语义对应。 然后我们可以应用学习的模型来重建对进行不可见动作的新主题进行部分变形的动态 4D 扫描 。 我们建议了两种方法, 将全球的变形与我们的神经变形模型融合起来。 实验显示了我们的方法在身份和外观的分解中的效果。 我们的方法也超越了传统的骨质驱动模型, 重建表层细节, 如棕榈或圆锥形, 不受固定模板的限制 。