Papers › Spatiality-guided Transformer for 3D Dense Captioning on Point Clouds

Spatiality-guided Transformer for 3D Dense Captioning on Point Clouds

22 Apr 2022arXiv:2204.10688archive 2025-07-28

Heng Wang, Chaoyi Zhang, Jianhui Yu, Weidong Cai

Dense captioning in 3D point clouds is an emerging vision-and-language task involving object-level 3D scene understanding. Apart from coarse semantic class prediction and bounding box regression as in traditional 3D object detection, 3D dense captioning aims at producing a further and finer instance-level label of natural language description on visual appearance and spatial relations for each scene object of interest. To detect and describe objects in a scene, following the spirit of neural machine translation, we propose a transformer-based encoder-decoder architecture, namely SpaCap3D, to transform objects into descriptions, where we especially investigate the relative spatiality of objects in 3D scenes and design a spatiality-guided encoder via a token-to-token spatial relation learning objective and an object-centric decoder for precise and spatiality-enhanced object caption generation. Evaluated on two benchmark datasets, ScanRefer and ReferIt3D, our proposed SpaCap3D outperforms the baseline method Scan2Cap by 4.94% and 9.61% in CIDEr@0.5IoU, respectively. Our project page with source code and supplementary files is available at https://SpaCap3D.github.io/ .

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Code

heng-hw/spacap3d officialmentioned in papermentioned on GitHubpytorch report

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Tasks

3D Object Detection3D dense captioningCaption GenerationDecoderDense CaptioningMachine TranslationObjectObject DetectionScene Understandingobject-detection

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
3D dense captioning Nr3D SpaCap3d BLEU-4 19.92 #9 of 10 Archive leaderboard report
3D dense captioning Nr3D SpaCap3d CIDEr 33.71 #9 of 10 Archive leaderboard report
3D dense captioning Nr3D SpaCap3d METEOR 22.61 #9 of 10 Archive leaderboard report
3D dense captioning Nr3D SpaCap3d ROUGE-L 50.50 #9 of 10 Archive leaderboard report
3D dense captioning ScanRefer Dataset SpaCap3d BLEU-4 35.30 #8 of 12 Archive leaderboard report
3D dense captioning ScanRefer Dataset SpaCap3d CIDEr 58.06 #8 of 12 Archive leaderboard report
3D dense captioning ScanRefer Dataset SpaCap3d METEOR 26.16 #8 of 12 Archive leaderboard report
3D dense captioning ScanRefer Dataset SpaCap3d ROUGE-L 55.03 #8 of 12 Archive leaderboard report

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Methods

Absolute Position EncodingsAdamAttentionBPEDense ConnectionsDropoutLabel SmoothingLayer NormalizationLinear LayerMulti-Head AttentionPosition-Wise Feed-Forward LayerResidual ConnectionSoftmaxTransformer

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