arXiv Machine Learning By Shi Chen, Weifeng Ge

Generative Semantic Scene Completion

Read the original on arXiv Machine Learning →

The paper introduces Generative Semantic Scene Completion (GSSC), a framework that recasts outdoor LiDAR semantic scene completion as a discrete diffusion process. It comprises three components: (1) paired sparse‑dense scene synthesis (PS³) to generate synthetic training data, (2) semantic‑guided generative scene completion (SGSC) that generates scenes from noise conditioned on sparse scans, and (3) structured source discrete diffusion (S²D²) that refines existing completions in a single flow‑matching step. Using this approach, the authors achieve state‑of‑the‑art performance on the SemanticKITTI benchmark, reaching 38.8% mIoU in a single‑sweep, single‑sample setting and 39.2% with limited augmentation.

Machine-generated by The Flow from the publisher's headline and feed description — not written or checked by a human. The full article lives at arXiv Machine Learning.

arXiv Computer Vision
Oct 5

PatchScene: Patch-based Voxel Diffusion for Large-Scale Scene Completion

PatchScene is a diffusion-based framework that completes large-scale LiDAR scenes using a patch-based voxel diffusion paradigm, generating fine-grained geometry in localized 3D regions. It incorporates a confidence-guided spatio-temporal fusion mechanism to merge overlapping patches and adjacent frames, and introduces an Annular-Flow diffusion strategy that propagates high-fidelity information from near to far ranges. Experiments on SemanticKITTI show state-of-the-art performance, with the model trained on 20 m LiDAR ranges generalizing to 50 m scenes without retraining.

By Qingdong Xu, Jiajun Zhu, Shilin Zhu, Xinjing He, Chao Lu, Huanran Wang, Jiyao Zhang
arXiv Computer Vision
Sep 14

Beyond Argmax: A Mechanistic Study of Semantic Retention in Frozen Foundation-Model Composition for Generalized Few-Shot 3D Segmentation

The paper investigates how much semantic information is lost when frozen foundation models are combined for few‑shot 3D segmentation. By varying the number of retained semantic alternatives before fusion, the authors show that keeping the full distribution of class scores yields higher harmonic‑mean IoU than collapsing to a single class. Experiments on ScanNet200 and ScanNet++ confirm that full‑distribution fusion consistently outperforms top‑1 and other operators, and that most useful information is recovered by retaining a compact set of plausible alternatives.

By Silas Kwabla Gah, Ebenezer Owusu
arXiv AI
Oct 12

GeoGR: Spatial-Semantic Token Compression and Group Routing for Efficient 3D VLMs

GeoGR introduces a two‑stage framework for efficient 3D vision‑language models. The first stage, GeoSemZip, compresses multi‑view visual tokens into compact 3D voxel representations while preserving important scene information through contextual anchors. The second stage, GroupRoute, dynamically routes tokens through the language model, allowing low‑relevance tokens to skip layers and rejoin later, thereby reducing computation without significant loss of performance.

By Yongxin Zheng, Hao Wu, Fang Li, Hu Fu, Peiran Yin, Xudong Wang, Haozhe Hu, Xinghao Chen, Yunpu Ma, Wei Zhang, Xiaoyu Shen