Reconstruct3D - 3D Reconstruction

Overview

The Reconstruct3D interface is used to generate 2D and 3D models from aerotriangulation results. It is typically used together with ReconstructAT to complete the full reconstruction workflow. This interface supports multiple output formats, tile processing, and fine parameter control.

Applicable Scenarios

• Generate 3D models from aerotriangulation results
• Generate orthophotos and digital surface models
• Tile reconstruction for large-scale data
• Need specific output formats

Interface Invocation

Command Line Invocation

reconstruct_full_engine(.exe) --reconstruct_type 2 --task_json config_task.json

Parameter Description

• reconstruct_type: Fixed as 2 (represents Reconstruct3D)
• task_json: Configuration file path

Configuration Parameters

Required Parameters

Parameter Name	Type	Description
working_dir	string	Working directory (must be the same as specified by the aerotriangulation interface)
gdal_folder	string	GDAL data path

Optional Parameters

Basic Parameters

Parameter Name	Type	Default Value	Description
input_image_type	int	0	Image type: 1=RGB, 2=Multispectral, 3=Infrared
resolution_level	int	1	Reconstruction accuracy: 1=High, 2=Medium, 3=Low
pipeline_mode	int	0	Reconstruction pipeline: 0=Pure visual reconstruction, 1=Pure lidar point cloud reconstruction
reconstruct_mode	int	0	Reconstruction mode: 0=General scene, 2=Power line scene
coordinate_system_3d	JSON	-	Output 3D result coordinate system, format see coordinate_system
coordinate_system_2d	JSON	-	Output 2D result coordinate system
min_avali_memory_size	double	0	Minimum available memory (GB), used to control tile count
fast_mode	bool	false	Fast mode, improves efficiency but reduces detail
keep_undistort_images	bool	false	Whether to keep undistorted images

Output Format Control [Must specify one of the following]

Parameter Name	Type	Default Value	Description
generate_osgb	bool	false	Generate OSGB format 3D model
generate_3d_tiles	bool	false	Generate 3D Tiles (b3dm) format
generate_las	bool	false	Generate LAS format point cloud
generate_pc_ply	bool	false	Generate PLY format point cloud
generate_pc_osgb	bool	false	Generate OSGB format point cloud LOD
generate_pc_pnts	bool	false	Generate pnts format point cloud LOD
generate_gs_ply	bool	false	Generate ply format Gaussian Splatting results
generate_obj	bool	false	Generate OBJ format textured mesh
generate_ply	bool	false	Generate PLY format textured mesh
generate_geotiff	bool	false	Generate GeoTIFF format orthophoto
generate_tile_2D	bool	false	Tile the orthophoto
generate_2D_from_3D_model	bool	false	Generate 2D orthophoto from 3D model

Advanced Parameters

Parameter Name	Type	Default Value	Description
use_draco_compression	bool	true	Whether to enable Draco vertex compression for 3D Tiles
tex_image_type_3dtiles	int	0	3D Tiles texture format: 0=JPEG, 1=WebP
use_gcj02	bool	false	Whether to convert orthophoto tiles to GCJ02 coordinate system

ROI Control

Parameter Name	Type	Default Value	Description
roi_for_2d	JSON	-	Region of interest for 2D reconstruction, format see ROI Structure Description
roi_for_3d	JSON	-	Region of interest for 3D reconstruction
roi_coordinate_system	JSON	WGS84	Coordinate system of ROI

ROI Structure Description

Field Name	Type	Description
boundary	array	2D boundary vertex set of ROI polygon
min_z	double	ROI minimum elevation
max_z	double	ROI maximum elevation

Example:

{
  "boundary": [              // 2D polygon boundary (counterclockwise)
    [x1, y1],
    [x2, y2],
    [x3, y3]
    // ...
  ],
  "min_z": 100.0,           // Minimum elevation
  "max_z": 500.0            // Maximum elevation
}

Complete Configuration Examples

Basic 3D Reconstruction

{
  "working_dir": "C:/Projects/3D_Task",
  "gdal_folder": "C:/MipMap/SDK/data",
  "input_image_type": 1,
  "resolution_level": 1,
  "generate_osgb": true,
  "generate_3d_tiles": true,
  "generate_geotiff": true
}

Specify Output Result Coordinate System

{
  "working_dir": "C:/Projects/3D_Task",
  "gdal_folder": "C:/MipMap/SDK/data",
  "input_image_type": 1,
  "resolution_level": 1,    
  "generate_osgb": true,
  "generate_3d_tiles": true,
  "generate_geotiff": true,
  "coordinate_system_3d": {
    "type": 3,
    "epsg_code": 32650        // WGS84 / UTM 50N
  },
  "coordinate_system_2d": {
    "type": 3,
    "epsg_code": 32650        // WGS84 / UTM 50N
  }
}

Set Reconstruction ROI

{
  "working_dir": "C:/Projects/3D_Task",
  "gdal_folder": "C:/MipMap/SDK/data",
  "input_image_type": 1,
  "resolution_level": 1,
  "roi_for_3d": {
    "boundary": [
      [114.12, 22.12],
      [114.13, 22.12],
      [114.13, 22.13],
      [114.12, 22.13]
    ],
    "min_z": 0,
    "max_z": 500
  },
  "generate_osgb": true,
  "generate_3d_tiles": true,
  "generate_geotiff": true,
  "coordinate_system_3d": {
    "type": 3,
    "epsg_code": 32650        // WGS84 / UTM 50N
  },
  "coordinate_system_2d": {
    "type": 3,
    "epsg_code": 32650        // WGS84 / UTM 50N
  }
}

Output Results

3D Model Output (/3D/)

• model-osgb/ - OSGB format model and LOD
• model-b3dm/ - 3D Tiles format (including tileset.json)
• model-obj/ - OBJ format model and textures
• point-las/ - LAS format point cloud
• point-ply/ - PLY format point cloud
• point-osgb/ - OSGB format point cloud LOD
• point-pnts/ - 3D Tiles point cloud format
• point-gs-ply/ - 3DGS-PLY point cloud format

2D Product Output (/2D/)

• geotiffs/ - GeoTIFF format orthophoto and DSM
• dom_tiles/ - Orthophoto tiles
• dsm_tiles/ - Digital surface model tiles

Resolution Level Description

Level	Description	Relative Processing Time	Applicable Scenarios
1	Ultra-high precision	3-5x	Professional surveying, cultural heritage protection
2	High precision	1x	General engineering applications
3	Quick preview	0.2-0.3x	Quick verification, preview

Error Handling

The interface returns an integer error code:

• 0: Success
• Non-zero: Various error conditions

For details, see Error Codes.

Common Questions

Q: Prompt "Cannot find aerotriangulation results"

A: Ensure:

• working_dir is the same as used by ReconstructAT
• Aerotriangulation has completed successfully
• milestones directory contains mvs.pb.bin file

Q: Insufficient memory error

A:

• Set min_avali_memory_size to limit memory usage
• Lower resolution_level
• Use DivideTiles for pre-tiling

Q: Incorrect output coordinates

A:

• Check coordinate_system_3d/2d settings
• Confirm ROI coordinate system matches data
• Verify GDAL data path is correct

Next Steps

• Learn about tile processing for large-scale data
• Study basic concepts to optimize reconstruction quality

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Tip: Reconstruct3D provides rich output options. It is recommended to quickly verify with low precision first, then perform high-quality reconstruction.