MoCapAnything V2: End-to-End Motion Capture for Arbitrary Skeletons

Fuente: arXiv
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Auteurs principaux: Gong, Kehong, Wen, Zhengyu, Phong, Dao Thien, Xu, Mingxi, He, Weixia, Wang, Qi, Zhang, Ning, Li, Zhengyu, Hou, Guanli, Lian, Dongze, He, Xiaoyu, Zhang, Mingyuan, Zhang, Hanwang
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Publié: 2026
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author Gong, Kehong
Wen, Zhengyu
Phong, Dao Thien
Xu, Mingxi
He, Weixia
Wang, Qi
Zhang, Ning
Li, Zhengyu
Hou, Guanli
Lian, Dongze
He, Xiaoyu
Zhang, Mingyuan
Zhang, Hanwang
author_facet Gong, Kehong
Wen, Zhengyu
Phong, Dao Thien
Xu, Mingxi
He, Weixia
Wang, Qi
Zhang, Ning
Li, Zhengyu
Hou, Guanli
Lian, Dongze
He, Xiaoyu
Zhang, Mingyuan
Zhang, Hanwang
contents Recent methods for arbitrary-skeleton motion capture from monocular video follow a factorized pipeline, where a Video-to-Pose network predicts joint positions and an analytical inverse-kinematics (IK) stage recovers joint rotations. While effective, this design is inherently limited, since joint positions do not fully determine rotations and leave degrees of freedom such as bone-axis twist ambiguous, and the non-differentiable IK stage prevents the system from adapting to noisy predictions or optimizing for the final animation objective. In this work, we present the first fully end-to-end framework in which both Video-to-Pose and Pose-to-Rotation are learnable and jointly optimized. We observe that the ambiguity in pose-to-rotation mapping arises from missing coordinate system information: the same joint positions can correspond to different rotations under different rest poses and local axis conventions. To resolve this, we introduce a reference pose-rotation pair from the target asset, which, together with the rest pose, not only anchors the mapping but also defines the underlying rotation coordinate system. This formulation turns rotation prediction into a well-constrained conditional problem and enables effective learning. In addition, our model predicts joint positions directly from video without relying on mesh intermediates, improving both robustness and efficiency. Both stages share a skeleton-aware Global-Local Graph-guided Multi-Head Attention (GL-GMHA) module for joint-level local reasoning and global coordination. Experiments on Truebones Zoo and Objaverse show that our method reduces rotation error from ~17 degrees to ~10 degrees, and to 6.54 degrees on unseen skeletons, while achieving ~20x faster inference than mesh-based pipelines. Project page: https://animotionlab.github.io/MoCapAnythingV2/
format Preprint
id arxiv_https___arxiv_org_abs_2604_28130
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle MoCapAnything V2: End-to-End Motion Capture for Arbitrary Skeletons
Gong, Kehong
Wen, Zhengyu
Phong, Dao Thien
Xu, Mingxi
He, Weixia
Wang, Qi
Zhang, Ning
Li, Zhengyu
Hou, Guanli
Lian, Dongze
He, Xiaoyu
Zhang, Mingyuan
Zhang, Hanwang
Computer Vision and Pattern Recognition
Recent methods for arbitrary-skeleton motion capture from monocular video follow a factorized pipeline, where a Video-to-Pose network predicts joint positions and an analytical inverse-kinematics (IK) stage recovers joint rotations. While effective, this design is inherently limited, since joint positions do not fully determine rotations and leave degrees of freedom such as bone-axis twist ambiguous, and the non-differentiable IK stage prevents the system from adapting to noisy predictions or optimizing for the final animation objective. In this work, we present the first fully end-to-end framework in which both Video-to-Pose and Pose-to-Rotation are learnable and jointly optimized. We observe that the ambiguity in pose-to-rotation mapping arises from missing coordinate system information: the same joint positions can correspond to different rotations under different rest poses and local axis conventions. To resolve this, we introduce a reference pose-rotation pair from the target asset, which, together with the rest pose, not only anchors the mapping but also defines the underlying rotation coordinate system. This formulation turns rotation prediction into a well-constrained conditional problem and enables effective learning. In addition, our model predicts joint positions directly from video without relying on mesh intermediates, improving both robustness and efficiency. Both stages share a skeleton-aware Global-Local Graph-guided Multi-Head Attention (GL-GMHA) module for joint-level local reasoning and global coordination. Experiments on Truebones Zoo and Objaverse show that our method reduces rotation error from ~17 degrees to ~10 degrees, and to 6.54 degrees on unseen skeletons, while achieving ~20x faster inference than mesh-based pipelines. Project page: https://animotionlab.github.io/MoCapAnythingV2/
title MoCapAnything V2: End-to-End Motion Capture for Arbitrary Skeletons
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2604.28130