We propose a novel optimization-based paradigm for 3D human model fitting on
images and scans. In contrast to existing approaches that directly regress the
parameters of a low-dimensional statistical body model (e.g. SMPL) from input
images, we train an ensemble of per-vertex neural fields network. The network
predicts, in a distributed manner, the vertex descent direction towards the
ground truth, based on neural features extracted at the current vertex
projection. At inference, we employ this network, dubbed LVD, within a
gradient-descent optimization pipeline until its convergence, which typically
occurs in a fraction of a second even when initializing all vertices into a
single point. An exhaustive evaluation demonstrates that our approach is able
to capture the underlying body of clothed people with very different body
shapes, achieving a significant improvement compared to state-of-the-art. LVD
is also applicable to 3D model fitting of humans and hands, for which we show a
significant improvement to the SOTA with a much simpler and faster method.

我们提出了一种新的基于优化的 3D 人体模型拟合范式，采用每个点的神经场网络进行训练，结合梯度下降优化管道实现对穿着衣服的人体的拟合。与现有的方法相比，这种方法能够捕获到具有非常不同身体形状的人的潜在身体，并在 3D 模型拟合中实现了显着改进。