Mosaic3D: Foundation Dataset and Model for Open-Vocabulary 3D Segmentation

Junha Lee, Chunghyun Park, Jaesung Choe, Yu-Chiang Frank Wang, Jan Kautz +2 more
2/10/2026

No official code found. Best implementation: NVlabs/Mosaic3D (70 stars, Apache-2.0, last commit 2026-01-06).

Abstract

We tackle open-vocabulary 3D scene segmentation tasks by introducing a novel data generation pipeline and training framework. Our work targets three essential aspects required for an effective dataset: precise 3D region segmentation, comprehensive textual descriptions, and sufficient dataset scale. By leveraging state-of-the-art open-vocabulary image segmentation models and region-aware vision-language models (VLM), we develop an automatic pipeline capable of producing high-quality 3D mask-text pairs. Applying this pipeline to multiple 3D scene datasets, we create Mosaic3D-5.6M, a dataset of more than 30K annotated scenes with 5.6M mask-text pairs - significantly larger than existing datasets. Building on these data, we propose Mosaic3D, a 3D visiual foundation model (3D-VFM) combining a 3D encoder trained with contrastive learning and a lightweight mask decoder for open-vocabulary 3D semantic and instance segmentation. Our approach achieves state-of-the-art results on open-vocabulary 3D semantic and instance segmentation benchmarks including ScanNet200, Matterport3D, and ScanNet++, with ablation studies validating the effectiveness of our large-scale training data. https://nvlabs.github.io/Mosaic3D/

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Code Implementations(1)

NVlabs/Mosaic3DCommunity25%
Apache-2.0

[CVPR 2025] Mosaic3D: Foundation Dataset and Model for Open-vocabulary 3D Segmentation

703Shell, PythonJan 21, 20259 months agoApache-2.0

Cite this paper

@article{lee2026mosaicd,
  title  = {Mosaic3D: Foundation Dataset and Model for Open-Vocabulary 3D Segmentation},
  author = {Junha Lee and Chunghyun Park and Jaesung Choe and Yu-Chiang Frank Wang and Jan Kautz and Minsu Cho and Christopher B. Choy},
  year   = {2026},
  eprint = {2502.02548},
  archivePrefix = {arXiv},
  url    = {https://arxiv.org/abs/2502.02548},
  journal = {CVPR 2025 2025}
}

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