Reconstruction Algorithm Explanation

• Parameters of reconstruction algorithm are filled in the parameters field of the POST /v2/jobs/<job-uuid>/start interface. The JSON object needs to be serialized into a string beforehand.
• The configuration of 2D, 3D, and LiDAR reconstruction jobs are filled in the parameter field.
• The predefine_AOI is an optional parameter, and is at the same level as the parameter. The predefine_AOI parameter only takes effect in 2D and 3D jobs.
• The export_parameter parameter, which is at the same level as the parameter parameter, is optional and sets the directory structure and content of reconstruction output.
• The values of type are different according to the job type. The type for 2D, 3D, and LiDAR reconstruction jobs are 14, 15, and 13 respectively.

{"resourceUuid": "{your resource uuid}", "parameters": "{\"parameter\": {}, \"predefine_AOI\": {}, \"export_parameter\": {}}", "type": number}

Common Section

Aerotriangulation and Point Cloud Result Parameters

Parameter Type	Parameter	Value Type	Default Value	Optional / Required	Explanation
Aerotriangulation Processing Parameter	SfM_method	enum_string	GLOBAL	Optional	Aerotriangulation algorithm. Optional values: "GLOBAL", "INCREMENTAL" If the majority of the images have precise locations with RTK (Real-Time Kinematic) data, "GLOBAL" is recommended. If the images have no GPS, "INCREMENTAL" is recommended.
	sfm_feature_quantity_level	enum_int	2	Optional	Maximum number of feature points. The optional values are 1, 2, 3. They respectively represent 4w, 2w, 9k.
	use_image_position	bool	true	Optional	Whether to use the location information recorded by image.
Aerotriangulation Result Parameter	generate_blocks_exchange_xml	bool	false	Optional	Whether to generate aerotriangulation result in CC format: BlocksExchange.xml
	blocks_exchange_xml_geo_desc	struct	{}	Optional	The output coordinate system of aerotriangulation result in CC format. The format is geo-desc-object. If images without GPS reconstruction is performed, this item can not be set to geographic coordinate system, set to the default value instead.
Point Cloud Result Parameter	output_pointcloud	bool	false	Optional	Whether to output point cloud result. Default: false When this item is set to true, the point cloud result parameter takes effect.
	generate_pnts	bool	true	Optional	Whether to generate the point cloud LOD model in pnts format. The model can be viewed by Terra software or Cesium webpage.
	generate_las	bool	false	Optional	Whether to generate point cloud model in LAS format.
	generate_point_s3mb	bool	false	Optional	Whether to generate point cloud model in s3mb format. The model can be viewed by SuperMap GIS software.
	generate_point_ply	bool	false	Optional	Whether to generate point cloud model in ply format.
	generate_pcd	bool	false	Optional	Whether to generate point cloud model in pcd format.
	merge_point	bool	false	Optional	Whether to merge the point cloud into one file.
Region of interest	max_altitude	float		Required	Maximum height (meter)
	min_altitude	float		Required	Minimum height (meter)
	polygon_points	three-dimensional floating array		Required	Polygon point set. It's used to describe the contour of interest region in horizontal direction. The format is `[[22.62832081, 113.9337651, 32.14], [22.6292795, 113.9333697, 33.585], [22.62957106, 113.9358513, 33.923]]`
	geo_desc	struct		Required	Coordinate system representation of `polygon_points`. The format can be checked from the "Geographic Coordinate System Described by WKT" or "Geographic Coordinate System Described by EPSG" of "Geographic Coordinate System" in this page.
Export Parameter	pc_dir_structure	bool	false	Required	Whether to keep the directory of cloud reconstruction output consistent with that of the local Terra software output and allow export files to be imported into Terra.
	undistort_images	bool	false	Optional	Whether to export the undistorted photos generated during the reconstruction process. This parameter is not supported for LiDAR point cloud tasks.
	temp_result_files	bool	false	Optional	Whether to export intermediate result files generated during the reconstruction process, which will occupy a large amount of storage space.

Geographic Coordinate System

Theoutput_geo_desc field of 2D, 3D and LiDAR jobs can be configured to one of the following coordinate systems.

Geographic Coordinate System Described by WKT

Parameter	Value Type	Default Value	Optional / Required	Explanation
cs_type	enum_string	GEO_CS	Optional	Geographic coordinate system. The optional values are "GEO_CS", "LOCAL_CS", "LOCAL_ENU_CS".
geo_cs_wkt	string	""	Optional	Coordinate system description. Please refer to Well-Known-Text format.
offset	array	[0.0, 0.0, 0.0]	Optional	Coordinate offset value. In the current coordinate system, apply an overall offset to the result coordinates.

Geographic Coordinate System Described by EPSG Code

Parameter	Value Type	Default Value	Optional / Required	Explanation
cs_type	enum_string	GEO_CS	Optional	Geographic coordinate system. The optional values are "GEO_CS", "LOCAL_CS", "LOCAL_ENU_CS".
geo_cs	string	""	Optional	Geographic coordinate system. Please refer to EPSG:4326 format.
override_vertical_cs	string	""	Optional	Override elevation coordinate system. Default is empty. The format is "EPSG:4326" (Bound to geo_cs).
offset	array	[0.0, 0.0, 0.0]	Optional	Coordinate offset value. In the current coordinate system, apply an overall offset to the result coordinates.

#### Local Coordinate System

Parameter	Value Type	Default Value	Optional / Required	Explanation
cs_type	enum_string	LOCAL_CS	Optional	Geographic coordinate system. The optional values are "GEO_CS", "LOCAL_CS", "LOCAL_ENU_CS".
offset	array	[0.0, 0.0, 0.0]	Optional	Coordinate offset value. In the current coordinate system, apply an overall offset to the result coordinates.

ENU Coordinate System

Parameter	Value Type	Default Value	Optional / Required	Explanation
cs_type	enum_string	LOCAL_ENU_CS	Optional	Geographic coordinate system. The optional values are "GEO_CS", "LOCAL_CS", "LOCAL_ENU_CS".
offset	array	[0.0, 0.0, 0.0]	Optional	Coordinate offset value. In the current coordinate system, apply an overall offset to the result coordinates.
ref_GPS	struct	{}	Optional	The reference origin GPS coordinates. For example, {"altitude": 23.0, "latitude": 28.0, "longitude": 113.0 }.

2D Reconstruction Algorithm Parameters

Parameter Type	Parameter	Value Type	Default Value	Optional / Required	Explanation
Aerotriangulation processing parameter	Read the Aerotriangulation Processing Parameter" of "Common Section"
Aerotriangulation result parameter	Read the "Aerotriangulation Result Parameter" of "Common Section"
2D reconstruction parameter	map_mode	enum_int		Required	Stitching image mode. Option values 0, 1, 2 correspond to farmland mode, city mode, orchard mode respectively.
	quality_level	enum_int	1	Optional	Option values 1, 2, 3 correspond to high precision, medium precision, low precision respectively.
	use_Wallis	bool	false	Optional	Whether to open uniforming color within the image. Suggested to enable when there is inconsistent brightness within a single image. It may result in contrast loss. Please use with caution.
	use_Dehaze	bool	false	Optional	Whether to enable image dehazing. It is recommended to enable when there is fog or haze in the captured images.
	use_gcj02	bool	false	Optional	Whether to use the National Geomatics Center coordinate system, only effective for map tiles.
	dom_tile_size	int	0	Optional	When this field is greater than 0, output results in blocks, indicating the DOM pixel size of a single block. This parameter must be a multiple of 2.
	output_geo_desc	struct	{}	Optional	Output coordinate system description. The format can be read from the "Geographic Coordinate System" table. Default {} represents no specified output coordinate system. The system will be automatically determined.
Range of interest region	predefine_AOI	struct	{}	Optional	Read the "Region of interest" of "Common Section"
Export Parameter	export_parameter	bool	false	Optional	Read the "Export Parameter" of "Common Section"

Example

Generate 2D Orthophoto Map of Urban Scene

{
  "parameter": {
    "map_mode": 1,
    "quality_level": 1,
    "output_geo_desc": {
      "cs_type": "GEO_CS",
      "geo_cs": "EPSG:32650",
      "geo_cs_wkt": "",
      "override_vertical_cs": ""
    }
  }
}

Output tiled 2D orthophoto maps for urban scenarios. The reconstruction output will be imported into Terra, and intermediate result files and reconstruction photos will not be exported.

{
  "export_parameter": {
    "pc_dir_structure": true,
    "undistort_images": false,
    "temp_result_files": false
  },
  "parameter": {
    "map_mode": 1,
    "quality_level": 1,
    "output_geo_desc": {
      "cs_type": "GEO_CS",
      "geo_cs": "EPSG:32650",
      "geo_cs_wkt": "",
      "override_vertical_cs": ""
    },
    "dom_tile_size": 5000
  }
}

3D Reconstruction Algorithm Parameters

Parameter Type	Parameter	Value Type	Default Value	Optional / Required	Explanation
Aerotriangulation processing parameter	Read the Aerotriangulation Processing Parameter" of "Common Section"
Aerotriangulation result parameter	Read the "Aerotriangulation Result Parameter" of "Common Section"
Point cloud result parameter	Read "Point Cloud Result Parameter" of "Common Section"
Texture model result parameter	output_mesh	bool	true	Optional	Whether to generate mesh When this item is set to true, the texture model result parameter takes effect.
	generate_ply	bool	true	Optional	Whether to generate texture model in ply format.
	generate_obj	bool	false	Optional	Whether to generate texture model in obj format.
	generate_b3dm	bool	true	Optional	Whether to generate mesh LOD model in b3dm format. The model can be viewed by Terra software or Cesium webpage.
	generate_osgb	bool	false	Optional	Whether to generate mesh LOD model in osgb format.
	generate_s3mb	bool	false	Optional	Whether to generate mesh LOD model in s3mb format. The model can be viewed by SuperMap GIS software.
	generate_i3s	bool	false	Optional	Whether to generate mesh LOD model in i3s format. The model can be viewed by ArcGIS software.
	water_refine	bool	false	Optional	Whether to enable water surface smoothing. It is recommended to enable when there is a large water area in the survey region that needs reconstruction.
	model_simplify	float	1.0	Optional	Simplify the number of model patches to a specified ratio (e.g., 0.2 corresponds to 20%). It is recommended to set this to a value less than 1 when using the LOD model for lightweight web browsing.The range is [0.05-1]. 1 represents no simplification.
Common parameter of point cloud and texture model	cut_AOI	bool	false	Optional	Whether to delete the section outside the capturing position. It is recommended to enable for data collected through POI capturing.
	quality_level	enum_int	2	Optional	The detail level of reconstruction. Option values 1, 2, 3 correspond to high precision, medium precision, low precision respectively.
	output_geo_desc	struct	{}	Optional	Output coordinate system description. The format is geo-desc-object. Default null represents no specified output coordinate system. The system will be automatically determined.
Range of interest region	predefine_AOI	struct	{}	Optional	Read the "Region of interest" of "Common Section
Export Parameter	export_parameter	bool	false	Optional	Read the "Export Parameter" of "Common Section"

Example

Generate Normal 3D Model

{
  "parameter": {
    "output_mesh": true,
    "generate_obj": true,
    "generate_b3dm": true,
    "generate_osgb": true
  }
}

Generate 3D models that require model editing. The reconstruction output will be imported into Terra, and reconstruction photos will be exported.

{
  "export_parameter": {
    "pc_dir_structure": true,
    "undistort_images": true,
    "temp_result_files": false
  },
  "parameter": {
    "generate_blocks_exchange_xml": true,
    "output_mesh": true,
    "generate_obj": true,
    "generate_b3dm": true,
    "generate_osgb": true,
    "output_geo_desc": {
      "cs_type": "GEO_CS",
      "geo_cs": "EPSG:32649",
      "geo_cs_wkt": "",
      "override_vertical_cs": ""
    }
  }
}

Generate 3D Model from POI Capture

{
  "parameter": {
    "cut_AOI": true,
    "output_mesh": true,
    "generate_obj": true,
    "generate_b3dm": true,
    "generate_osgb": true,
    "output_geo_desc": {
      "cs_type": "GEO_CS",
      "geo_cs": "EPSG:32649",
      "geo_cs_wkt": "",
      "override_vertical_cs": ""
    }
  }
}

Generate 3D Point Cloud Model of Power Line

{
  "parameter": {
    "output_pointcloud": true,
    "generate_pnts": true,
    "generate_las": true,
    "output_geo_desc": {
      "cs_type": "GEO_CS",
      "geo_cs": "EPSG:32649",
      "geo_cs_wkt": "",
      "override_vertical_cs": ""
    }
  }
}

LiDAR Reconstruction Algorithm Parameters

Parameter Type	Parameter	Value Type	Default Value	Optional / Required	Explanation
Common processing parameter	colorize_point	bool	true	Optional	Whether to colorize the LiDAR point cloud.
	lpp_optimise	bool	false	Optional	Whether to perform ICP (Iterative Closest Point) optimization on the LiDAR point cloud.
	refine_calibrate	int	0	Optional	Whether to perform self-calibration. 0 means no. 1 means yes.
	lidar_point_max_distance	int	300	Optional	The maximum effective distance of the LiDAR point cloud. Points beyond this distance will be clipped.
	smooth_point	bool	false	Optional	Whether to smooth the LiDAR point cloud.
	sample_distance	float	0	Optional	Sampling distance for voxel downsampling of the LiDAR point cloud. Default is 0, which means no. If you only want to downsample based on voxelization, `quality_level` should be set to 1.
	output_height_offset	float	0	Optional	Height offset value. Apply vertical offset to the output results.
	quality_level	enum_int	2	Optional	Sampling rate for temporal downsampling of the point cloud. Option values 1, 2, 3 correspond to 100%, 25%, 6.25%. It conflicts with the setting of `sample_distance`. Typically, choose either voxel downsampling or temporal downsampling.
	output_geo_desc	struct	{}	Optional	Output coordinate system description. Default {} represents no specified output coordinate system. The system will be automatically determined.
Point cloud result parameter	Read the "Point Cloud Result Parameter" of "Common Section"
Ground point extraction parameter	ground_extract	bool	false	Optional	Whether to extract ground points
	scene_type	enum_int	1	Optional	Ground scene type. Option values 0, 1, 2 correspond to flat ground, slope and gentle slope.
	max_size_building	float	20	Optional	The diagonal length of the largest building in the scene. The range is [1, 1000].
	iter_dist	float	The default value varies with the scene type.	Optional	Iterative distance. The scene_type has flat ground, slope and gentle slope. The default values are 0.3, 0.5, 0.7 respectively. The range is [0.01, 10].
	iter_angle	float	The default value varies with the scene type.	Optional	Iterative angle. The scene_type has flat ground, slope and gentle slope. The default values are 3, 6, 10 respectively. The range is [0.01, 60].
DEM result parameter	generate_dem	bool	false	Optional	Whether to generate DEM
	dem_resolution	float	2.0	Optional	DEM resolution. The unit is meter. Default is 2.0. The range is [0.05, 50].
Export Parameter	export_parameter	bool	false	Optional	Read the "Export Parameter" of "Common Section"

Example

Generate DEM

{
  "parameter": {
    "output_pointcloud": true,
    "generate_las": true,
    "generate_dem": true,
    "dem_resolution": 2.0,
    "ground_extract": true,
    "scene_type": 1,
    "max_size_building": 20,
    "output_geo_desc": {
      "cs_type": "GEO_CS",
      "geo_cs": "EPSG:32649",
      "geo_cs_wkt": "",
      "override_vertical_cs": ""
    }
  }
}

Generate a 3D point cloud model after point cloud optimization. The reconstruction output will be imported into Terra, and intermediate result files generated during the reconstruction process will be exported.

{
  "export_parameter": {
    "pc_dir_structure": true,
    "undistort_images": false,
    "temp_result_files": true
  },
  "parameter": {
    "lpp_optimise": true,
    "output_pointcloud": true,
    "generate_pnts": true,
    "generate_las": true,
    "output_geo_desc": {
      "cs_type": "GEO_CS",
      "geo_cs": "EPSG:32649",
      "geo_cs_wkt": "",
      "override_vertical_cs": ""
    }
  }
}

Generate 3D Point Cloud Model of Voxel Downsampling

{
  "parameter": {
    "sample_distance": 0.2,
    "output_pointcloud": true,
    "generate_pnts": true,
    "generate_las": true,
    "output_geo_desc": {
      "cs_type": "GEO_CS",
      "geo_cs": "EPSG:32649",
      "geo_cs_wkt": "",
      "override_vertical_cs": ""
    }
  }
}

Reconstruction Results Explanation and Quality Report

• The output of TerraAPI is consistent with DJI Terra software. For a detailed explanation of the results, see the DJI Terra Operation Guide
• The reconstruction quality reports in json format are at:
  • AT，AT/report/sfm_report.json
  • 2D，report/map_report.json
  • 3D，report/model_report.json
  • LiDAR，report/report.json