AVGGT: Rethinking Global Attention for Accelerating VGGT

Fuente: arXiv
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Autori principali: Sun, Xianbing, Zhu, Zhikai, Lou, Zhengyu, Yang, Bo, Tang, Jinyang, Zhang, Liqing, Wang, He, Zhang, Jianfu
Natura: Preprint
Pubblicazione: 2025
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author Sun, Xianbing
Zhu, Zhikai
Lou, Zhengyu
Yang, Bo
Tang, Jinyang
Zhang, Liqing
Wang, He
Zhang, Jianfu
author_facet Sun, Xianbing
Zhu, Zhikai
Lou, Zhengyu
Yang, Bo
Tang, Jinyang
Zhang, Liqing
Wang, He
Zhang, Jianfu
contents Models such as VGGT and $π^3$ have shown strong multi-view 3D performance, but their heavy reliance on global self-attention results in high computational cost. Existing sparse-attention variants offer partial speedups, yet lack a systematic analysis of how global attention contributes to multi-view reasoning. In this paper, we first conduct an in-depth investigation of the global attention modules in VGGT and $π^3$ to better understand their roles. Our analysis reveals a clear division of roles in the alternating global-frame architecture: early global layers do not form meaningful correspondences, middle layers perform cross-view alignment, and last layers provide only minor refinements. Guided by these findings, we propose a training-free two-step acceleration scheme: (1) converting early global layers into frame attention, and (2) subsampling global attention by subsampling K/V over patch tokens with diagonal preservation and a mean-fill component. We instantiate this strategy on VGGT and $π^3$ and evaluate across standard pose and point-map benchmarks. Our method achieves substantial inference acceleration across different context lengths, yielding about $2\times$ speedup at 100 frames, $4$--$5\times$ at 300 frames, and $8$--$10\times$ at 800 frames, while matching or slightly improving the accuracy of the original models and remaining robust in extremely dense multi-view settings where prior sparse-attention baselines fail.
format Preprint
id arxiv_https___arxiv_org_abs_2512_02541
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle AVGGT: Rethinking Global Attention for Accelerating VGGT
Sun, Xianbing
Zhu, Zhikai
Lou, Zhengyu
Yang, Bo
Tang, Jinyang
Zhang, Liqing
Wang, He
Zhang, Jianfu
Computer Vision and Pattern Recognition
Models such as VGGT and $π^3$ have shown strong multi-view 3D performance, but their heavy reliance on global self-attention results in high computational cost. Existing sparse-attention variants offer partial speedups, yet lack a systematic analysis of how global attention contributes to multi-view reasoning. In this paper, we first conduct an in-depth investigation of the global attention modules in VGGT and $π^3$ to better understand their roles. Our analysis reveals a clear division of roles in the alternating global-frame architecture: early global layers do not form meaningful correspondences, middle layers perform cross-view alignment, and last layers provide only minor refinements. Guided by these findings, we propose a training-free two-step acceleration scheme: (1) converting early global layers into frame attention, and (2) subsampling global attention by subsampling K/V over patch tokens with diagonal preservation and a mean-fill component. We instantiate this strategy on VGGT and $π^3$ and evaluate across standard pose and point-map benchmarks. Our method achieves substantial inference acceleration across different context lengths, yielding about $2\times$ speedup at 100 frames, $4$--$5\times$ at 300 frames, and $8$--$10\times$ at 800 frames, while matching or slightly improving the accuracy of the original models and remaining robust in extremely dense multi-view settings where prior sparse-attention baselines fail.
title AVGGT: Rethinking Global Attention for Accelerating VGGT
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2512.02541