SK-TreePCN: Skeleton-Embedded Transformer Model for Point Cloud Completion of Individual Trees from Simulated to Real Data

Tree structural information is essential for studying forest ecosystem functions, driving mechanisms, and global change response mechanisms. Although current terrestrial laser scanning (TLS) can acquire high-precision 3D structural information of forests, mutual occlusion between trees, the scanner’...

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Main Authors: Haifeng Xu, Yongjian Huai, Xun Zhao, Qingkuo Meng, Xiaoying Nie, Bowen Li, Hao Lu
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Remote Sensing
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Online Access:https://www.mdpi.com/2072-4292/17/4/656
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author Haifeng Xu
Yongjian Huai
Xun Zhao
Qingkuo Meng
Xiaoying Nie
Bowen Li
Hao Lu
author_facet Haifeng Xu
Yongjian Huai
Xun Zhao
Qingkuo Meng
Xiaoying Nie
Bowen Li
Hao Lu
author_sort Haifeng Xu
collection DOAJ
description Tree structural information is essential for studying forest ecosystem functions, driving mechanisms, and global change response mechanisms. Although current terrestrial laser scanning (TLS) can acquire high-precision 3D structural information of forests, mutual occlusion between trees, the scanner’s field of view, and terrain changes make the point clouds captured by laser scanning sensors incomplete, further hindering downstream tasks. This study proposes a skeleton-embedded tree point cloud completion method, termed SK-TreePCN, which recovers complete individual tree point clouds from incomplete scanning data in the field. SK-TreePCN employs a transformer trained on simulated point clouds generated by a 3D radiative transfer model. Unlike existing point cloud completion algorithms designed for regular shapes and simple structures, the SK-TreePCN method addresses structurally heterogeneous trees. The 3D radiative transfer model LESS, which can simulate various TLS data over highly heterogeneous scenes, is employed to generate massive point clouds with training labels. Among the various point cloud completion methods evaluated, SK-TreePCN exhibits outstanding performance regarding the Chamfer distance (CD) and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>F</mi><mn>1</mn></mrow></semantics></math></inline-formula> Score. The generated point clouds display a more natural appearance and clearer branches. The accuracy of tree height and diameter at breast height extracted from the recovered point cloud achieved <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi mathvariant="bold-italic">R</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula> values of 0.929 and 0.904, respectively. SK-TreePCN demonstrates applicability and robustness in recovering individual tree point clouds. It demonstrated great potential for TLS-based field measurements of trees, refining point cloud 3D reconstruction and tree information extraction and reducing field data collection labor while retaining satisfactory data quality.
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issn 2072-4292
language English
publishDate 2025-02-01
publisher MDPI AG
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series Remote Sensing
spelling doaj-art-4144f97c7bd54ea291b3ab9f0a7786a02025-08-20T03:12:19ZengMDPI AGRemote Sensing2072-42922025-02-0117465610.3390/rs17040656SK-TreePCN: Skeleton-Embedded Transformer Model for Point Cloud Completion of Individual Trees from Simulated to Real DataHaifeng Xu0Yongjian Huai1Xun Zhao2Qingkuo Meng3Xiaoying Nie4Bowen Li5Hao Lu6School of Information Science and Technology, Beijing Forestry University, Beijing 100083, ChinaSchool of Information Science and Technology, Beijing Forestry University, Beijing 100083, ChinaState Forestry and Grassland Administration Key Laboratory of Forest Resources and Environmental Management, Beijing Forestry University, Beijing 100083, ChinaSchool of Information Science and Technology, Beijing Forestry University, Beijing 100083, ChinaSchool of Information Science and Technology, Beijing Forestry University, Beijing 100083, ChinaResearch Institute of Forest Resource Information Techniques, Chinese Academy of Forestry, Beijing 100091, ChinaSchool of Information Science and Technology, Beijing Forestry University, Beijing 100083, ChinaTree structural information is essential for studying forest ecosystem functions, driving mechanisms, and global change response mechanisms. Although current terrestrial laser scanning (TLS) can acquire high-precision 3D structural information of forests, mutual occlusion between trees, the scanner’s field of view, and terrain changes make the point clouds captured by laser scanning sensors incomplete, further hindering downstream tasks. This study proposes a skeleton-embedded tree point cloud completion method, termed SK-TreePCN, which recovers complete individual tree point clouds from incomplete scanning data in the field. SK-TreePCN employs a transformer trained on simulated point clouds generated by a 3D radiative transfer model. Unlike existing point cloud completion algorithms designed for regular shapes and simple structures, the SK-TreePCN method addresses structurally heterogeneous trees. The 3D radiative transfer model LESS, which can simulate various TLS data over highly heterogeneous scenes, is employed to generate massive point clouds with training labels. Among the various point cloud completion methods evaluated, SK-TreePCN exhibits outstanding performance regarding the Chamfer distance (CD) and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>F</mi><mn>1</mn></mrow></semantics></math></inline-formula> Score. The generated point clouds display a more natural appearance and clearer branches. The accuracy of tree height and diameter at breast height extracted from the recovered point cloud achieved <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi mathvariant="bold-italic">R</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula> values of 0.929 and 0.904, respectively. SK-TreePCN demonstrates applicability and robustness in recovering individual tree point clouds. It demonstrated great potential for TLS-based field measurements of trees, refining point cloud 3D reconstruction and tree information extraction and reducing field data collection labor while retaining satisfactory data quality.https://www.mdpi.com/2072-4292/17/4/656point cloud completionindividual treetree skeletonterrestrial laser scanningsimulation
spellingShingle Haifeng Xu
Yongjian Huai
Xun Zhao
Qingkuo Meng
Xiaoying Nie
Bowen Li
Hao Lu
SK-TreePCN: Skeleton-Embedded Transformer Model for Point Cloud Completion of Individual Trees from Simulated to Real Data
Remote Sensing
point cloud completion
individual tree
tree skeleton
terrestrial laser scanning
simulation
title SK-TreePCN: Skeleton-Embedded Transformer Model for Point Cloud Completion of Individual Trees from Simulated to Real Data
title_full SK-TreePCN: Skeleton-Embedded Transformer Model for Point Cloud Completion of Individual Trees from Simulated to Real Data
title_fullStr SK-TreePCN: Skeleton-Embedded Transformer Model for Point Cloud Completion of Individual Trees from Simulated to Real Data
title_full_unstemmed SK-TreePCN: Skeleton-Embedded Transformer Model for Point Cloud Completion of Individual Trees from Simulated to Real Data
title_short SK-TreePCN: Skeleton-Embedded Transformer Model for Point Cloud Completion of Individual Trees from Simulated to Real Data
title_sort sk treepcn skeleton embedded transformer model for point cloud completion of individual trees from simulated to real data
topic point cloud completion
individual tree
tree skeleton
terrestrial laser scanning
simulation
url https://www.mdpi.com/2072-4292/17/4/656
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AT yongjianhuai sktreepcnskeletonembeddedtransformermodelforpointcloudcompletionofindividualtreesfromsimulatedtorealdata
AT xunzhao sktreepcnskeletonembeddedtransformermodelforpointcloudcompletionofindividualtreesfromsimulatedtorealdata
AT qingkuomeng sktreepcnskeletonembeddedtransformermodelforpointcloudcompletionofindividualtreesfromsimulatedtorealdata
AT xiaoyingnie sktreepcnskeletonembeddedtransformermodelforpointcloudcompletionofindividualtreesfromsimulatedtorealdata
AT bowenli sktreepcnskeletonembeddedtransformermodelforpointcloudcompletionofindividualtreesfromsimulatedtorealdata
AT haolu sktreepcnskeletonembeddedtransformermodelforpointcloudcompletionofindividualtreesfromsimulatedtorealdata