arXiv Machine Learning

Generative Semantic Scene Completion

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.

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
arXiv Machine Learning
Sep 4

Sparse auto-regressive modeling for scene generation from multi-view images

The paper introduces SPAR3S, a sparse voxel‑aligned 3D latent generative model that completes 3D scenes from sparse, unconstrained multi‑view images. It learns a compact voxel‑aligned latent space using photometric supervision via differentiable 3D Gaussian Splatting, and employs a masked autoregressive transformer to predict missing voxel occupancy and latent tokens. Experiments on synthetic indoor scenes and RealEstate10k show that SPAR3S achieves higher novel‑view quality than prior methods and generalizes to real‑world data.

By Thomas Lucas, Maxime Pietrantoni, Philippe Weinzaepfel, Wonjune Cho, Bardienus Pieter Duisterhof, Vincent Leroy, Jerome Revaud
arXiv Computer Vision
Sep 11

FastMap: Real-Time Semantic Map Completion via Bitwise Masked Modeling

FastMap is a lightweight two‑stage framework that completes top‑down categorical semantic maps in real time. It first compresses map patches into compact bitwise tokens using a lookup‑free BitVAE, producing a 0.41 GB model that is 3.7× smaller than prior masked‑modeling baselines. A Masked AutoEncoder transformer then reconstructs missing tokens in a single forward pass (0.011 s per map), and an object‑aware masking strategy enables goal‑conditioned generation without extra inference cost. On the Gibson benchmark, FastMap attains 34.10 % mIoU and 45.84 % semantic Success Rate, more than doubling the previous best, and achieves an 83.8 % Success Rate on downstream ObjectNav, the highest among compared navigation methods.

By Yijie Deng, Shuaihang Yuan, Congcong Wen, Hao Huang, Anthony Tzes
arXiv Computer Vision
Oct 2

PixelDense: Dense Prediction as Representation Alignment for Pixel Diffusion

PixelDense introduces a dual‑stream representation alignment for pixel diffusion, separating semantic and geometric teachers (DINOv2, SAM2, Depth Anything v2, Metric3D v2) into distinct projection spaces with an orthogonality penalty. The method improves dense‑prediction benchmarks, boosting PixelGen‑XXL’s GenEval score from 0.7927 to 0.8093, achieving significant gains in panoptic quality and depth accuracy, and accelerating training from random initialization. It also enhances SDEdit editing by preserving background structure and increasing PSNR.

By Lehan Yang, Daiqing Qi, Wenhao Zhang, Avery Li, Yiqing Yang, Yifan Li, Yu Kong, Haitian Zheng, Zhifei Zhang, Zhe Lin, Varun Jampani, Sheng Li
arXiv Computer Vision
Oct 12

Improving Semantic Coverage in AI Test & Evaluation through Generative Augmentation

The paper introduces a three‑stage generative AI pipeline to identify and fill semantic gaps in AI test datasets without requiring labeled data. First, vision‑language models zero‑shot label semantic factors and clustering highlights those most impacting model behavior. Second, diffusion‑based image‑to‑image models generate new images that preserve scene content while adding underrepresented semantics. Third, statistical checks confirm improved coverage before the synthetic images augment the test set. The method is validated on image classification and object detection tasks, showing that enriched test sets better differentiate models with or without exposure to missing semantics, leading to conclusions that align more closely with an ideally covered dataset.

By Connor Hashemi, Bharadwaj Ravichandran, Connor Anderson, Shitij Govil, Brandon RichardWebster, Brian Hu, Keith Fieldhouse
arXiv Computer Vision
Oct 16

SUPRA-TEX: 3D Generation with Super-Aligned Texture

SUPRA-Tex is a new method for single‑image 3D generation that dresses a 3D mesh with relightable materials while preserving the visual details of a reference image. It decouples visible‑material estimation, surface alignment, and observation‑guided 3D completion, allowing a 3D generator trained on limited data to focus on preserving visible evidence and completing unobserved surfaces. The approach uses an MLLM‑based image editor to predict lighting‑separated PBR maps, projects them onto the visible surface, encodes them with a pretrained material VAE, and employs an interleaved flow transformer to generate complete material latents, achieving state‑of‑the‑art performance on geometry‑conditioned texturing and end‑to‑end asset generation.

By Chen Yang, Jiemin Fang, Fanpeng Meng, Zihao Huang, Jichen Pang, Guanjun Wu, Zhikuan Bao, Qi Tian