LiteGE: Shape Descriptor Creation Process
Figure 1: Illustration of shape descriptor creation process in LiteGE. First, each input point cloud is aligned to a canonical upright orientation. Next, the shape is voxelized and the informative voxels near the shapes surface are selected. Finally, we compute the unsigned distance (UDF) from the informative voxels to the shape to construct the final shape descriptor. This is as shown on the rightmost figure where we depicted the cross-section slice of the UDF heatmap through the center of the shape.
Paper context
Paper title: LiteGE: Lightweight Geodesic Embedding for Efficient Geodesics Computation and Non-Isometric Shape Correspondence Abstract: Computing geodesic distances on 3D surfaces is fundamental to many tasks in 3D vision and geometry processing, with deep connections to tasks such as shape correspondence. Recent learning-based methods achieve strong performance but rely on large 3D backbones, leading to high memory usage and latency, which limit their use in interactive or resource-constrained settings. We introduce LiteGE, a lightweight approach that constructs compact, category-aware shape descriptors by applying Principal Component Analysis (PCA) to unsigned distance field (UDFs) samples at informative voxels. This descriptor is efficient to compute and removes the need for high-capacity networks. LiteGE remains robust on sparse point clouds, supporting inputs with as few as 300 points, where prior methods fail. Extensive experiments show that LiteGE reduces memory usage and inference time by up to 300$\times$ compared to existing neural approaches. In addition, by exploiting the intrinsic relationship between geodesic distance and shape correspondence, LiteGE enables fast and accurate shape matching. Our method achieves up to 1000$\times$ speedup over state-of-the-art mesh-based approaches while maintaining comparable accuracy on non-isometric shape pairs, including evaluations on point-cloud inputs. Passages referencing this figure: Figure 1: Illustration of shape descriptor creation process in LiteGE. The overall pipeline is illustrated in Figure 1 . Each voxel is assigned a value of 1 if it lies within the shape and 0 otherwise (Figure 1 , middle).
