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28.1.13. Point Cloud Data Management

NEW in 3.32

Nota

These algorithms are only available if QGIS uses the PDAL library version 2.5.0 or newer.

28.1.13.1. Assign projection

Assigns a Coordinate Reference System to a point cloud layer, if it is missing or wrong. A new layer is created.

Veja também

Reproject

Parâmetros

Label	Nome	Type	Descrição
Input layer	INPUT	[point cloud]	Input point cloud layer to assign a CRS to
Desired CRS	CRS	[crs]	The CRS to apply to the layer
Output layer	OUTPUT	[point cloud] Default: [Save to temporary file]	Specify the point cloud file to use as output. One of: Save to a Temporary File Save to File…

Resultados

Label	Nome	Type	Descrição
Converted	OUTPUT	[point cloud]	Output point cloud layer with a new CRS. Currently supported formats are .LAS, .LAZ, .COPC.LAZ and .VPC.

Python code

Algorithm ID: pdal:assignprojection

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Usando os algoritmos do processamento a partir da consola for details on how to run processing algorithms from the Python console.

28.1.13.2. Build virtual point cloud (VPC)

Creates a virtual point cloud (VPC) from input point cloud data.

If you leave the optional parameters unchecked, the VPC file will be built very quickly as the algorithm will only read metadata of input files. With any of the optional parameters set, the algorithm will read all points which can take some time.

Fig. 28.13 Generating Virtual Point Cloud with overview from a set of point cloud tiles

Veja também

Merge

Parâmetros

Label	Nome	Type	Descrição
Input layers	LAYERS	[point cloud] [list]	Input point cloud layers to combine inside a virtual point cloud layer
Calculate boundary polygon	BOUNDARY	[boolean] Default: False	Set to True to show the exact boundaries of data (rather than just rectangular extent)
Calculate statistics	STATISTICS	[boolean] Default: False	Set to True to understand ranges of values of the various attributes
Build overview point cloud	OVERVIEW	[boolean] Default: False	Generates a single “thinned” point cloud of all the input data (using only every 1000th point from original data). The overview point cloud will be created next to the VPC file - for example, for mydata.vpc, the overview point cloud would be named mydata-overview.copc.laz.
Virtual point cloud	OUTPUT	[point cloud] Default: [Save to temporary file]	Specify the point cloud file to build the data into. One of: Save to a Temporary File Save to File…

Resultados

Label	Nome	Type	Descrição
Virtual point cloud	OUTPUT	[raster]	Output point cloud layer combining all the input data, as a virtual file.

Python code

Algorithm ID: pdal:virtualpointcloud

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Usando os algoritmos do processamento a partir da consola for details on how to run processing algorithms from the Python console.

28.1.13.3. Clip

Clips a point cloud layer by a polygon layer so that the resulting point cloud contains only points within the polygons.

Fig. 28.14 Clipping an input point cloud layer with a polygon coverage

Parâmetros

Basic parameters

Label	Nome	Type	Descrição
Input layer	INPUT	[point cloud]	Input point cloud layer to clip
Clipping polygons	OVERLAY	[vector: polygon]	Polygon vector layer to use as coverage for clipping the points
Clipped	OUTPUT	[point cloud] Default: [Save to temporary file]	Specify the point cloud file to export the clipped points to. One of: Save to a Temporary File Save to File…

Advanced parameters

Label	Nome	Type	Descrição
Filter expression Opcional	FILTER_EXPRESSION	[expression]	A PDAL expression for selecting a subset of features in the point cloud data
Cropping extent Opcional	FILTER_EXTENT	[extent]	A map extent for selecting a subset of features in the point cloud data Available methods are: Calculate from layer…: uses extent of a layer loaded in the current project Calculate from layout map…: uses extent of a layout map item in the active project Calculate from bookmark…: uses extent of a saved bookmark Use map canvas extent Draw on canvas: click and drag a rectangle delimiting the area to take into account Enter the coordinates as xmin, xmax, ymin, ymax

Resultados

Label	Nome	Type	Descrição
Clipped	OUTPUT	[raster]	Output point cloud whose features are the points within the coverage polygon layer.

Python code

Algorithm ID: pdal:clip

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Usando os algoritmos do processamento a partir da consola for details on how to run processing algorithms from the Python console.

28.1.13.4. Create COPC

Creates the index for all the input point cloud files in a batch mode.

Parâmetros

Label	Nome	Type	Descrição
Input layers	LAYERS	[point cloud] [list]	Input point cloud layers to create an index for
Output directory Opcional	OUTPUT	[folder] Default: [Skip output]	Specify the folder to create the new files in. One of: Skip Output Save to a Temporary Directory Save to Directory

Resultados

Label	Nome	Type	Descrição
Output directory	OUTPUT	[folder]	Output folder containing point cloud layers with accompanying COPC index files.

Python code

Algorithm ID: pdal:createcopc

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Usando os algoritmos do processamento a partir da consola for details on how to run processing algorithms from the Python console.

28.1.13.5. Information

Outputs basic metadata from an input point cloud file.

Example of output information:

LAS           1.4
point format  6
count         56736130
scale         0.001 0.001 0.001
offset        431749.999 5440919.999 968.898
extent        431250 5440420 424.266
              432249.999 5441419.999 1513.531
crs           ETRS89 / UTM zone 34N (N-E) (EPSG:3046)  (vertical CRS missing!)
units         horizontal=metre  vertical=unknown

Attributes:
- X floating 8
- Y floating 8
- Z floating 8
- Intensity unsigned 2
- ReturnNumber unsigned 1
- NumberOfReturns unsigned 1
- ScanDirectionFlag unsigned 1
- EdgeOfFlightLine unsigned 1
- Classification unsigned 1
- ScanAngleRank floating 4
- UserData unsigned 1
- PointSourceId unsigned 2
- GpsTime floating 8
- ScanChannel unsigned 1
- ClassFlags unsigned 1

Parâmetros

Label	Nome	Type	Descrição
Input layer	INPUT	[point cloud]	Input point cloud layer to extract metadata information from
Layer information	OUTPUT	[file] Default: [Save to temporary file]	Specify the file to store the metadata information. One of: Save to a Temporary File Save to File…

Resultados

Label	Nome	Type	Descrição
Layer information	OUTPUT	[vector]	HTML file to store the metadata information.

Python code

Algorithm ID: pdal:info

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Usando os algoritmos do processamento a partir da consola for details on how to run processing algorithms from the Python console.

28.1.13.6. Merge

Merges multiple point cloud files into a single one.

Veja também

Build virtual point cloud (VPC)

Parâmetros

Basic parameters

Label	Nome	Type	Descrição
Input layers	LAYERS	[point cloud] [list]	Input point cloud layers to merge into a single one
Merged	OUTPUT	[point cloud] Default: [Save to temporary file]	Specify the output point cloud merging input files. One of: Save to a Temporary File Save to File…

Advanced parameters

Label	Nome	Type	Descrição
Filter expression Opcional	FILTER_EXPRESSION	[expression]	A PDAL expression for selecting a subset of features in the point cloud data
Cropping extent Opcional	FILTER_EXTENT	[extent]	A map extent for selecting a subset of features in the point cloud data Available methods are: Calculate from layer…: uses extent of a layer loaded in the current project Calculate from layout map…: uses extent of a layout map item in the active project Calculate from bookmark…: uses extent of a saved bookmark Use map canvas extent Draw on canvas: click and drag a rectangle delimiting the area to take into account Enter the coordinates as xmin, xmax, ymin, ymax

Resultados

Label	Nome	Type	Descrição
Merged	OUTPUT	[point cloud]	Output point cloud layer merging all the input files.

Python code

Algorithm ID: pdal:merge

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Usando os algoritmos do processamento a partir da consola for details on how to run processing algorithms from the Python console.

28.1.13.7. Reproject

Reprojects a point cloud to a different Coordinate Reference System (CRS).

Veja também

Assign projection

Parâmetros

Label	Nome	Type	Descrição
Input layer	INPUT	[point cloud]	Input point cloud layer to reproject to a different CRS
Target CRS	CRS	[crs]	The CRS to apply to the layer
Reprojected	OUTPUT	[point cloud] Default: [Save to temporary file]	Specify the reprojected point cloud file. One of: Save to a Temporary File Save to File…

Advanced parameters

Label	Nome	Type	Descrição
Coordinate operation Opcional	OPERATION	[datum]	The datum transformation to use to reproject the data between the origin and target systems.

Resultados

Label	Nome	Type	Descrição
REPROJECTED	OUTPUT	[point cloud]	Output point cloud layer in the target CRS.

Python code

Algorithm ID: pdal:reproject

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Usando os algoritmos do processamento a partir da consola for details on how to run processing algorithms from the Python console.

28.1.13.8. Thin (by sampling radius)

Creates a thinned version of the point cloud by performing sampling by distance point (reduces the number of points within a certain radius).

Fig. 28.15 Thining point cloud (by sampling radius)

Veja também

Thin (by skipping points)

Parâmetros

Basic parameters

Label	Nome	Type	Descrição
Input layer	INPUT	[point cloud]	Input point cloud layer to create a thinned version from
Sampling radius (in map units)	SAMPLING_RADIUS	[number] Default: 1.0	Distance within which points are sampled to a unique point
Thinned (by radius)	OUTPUT	[point cloud] Default: [Save to temporary file]	Specify the output point cloud with reduced points. One of: Save to a Temporary File Save to File…

Advanced parameters

Label	Nome	Type	Descrição
Filter expression Opcional	FILTER_EXPRESSION	[expression]	A PDAL expression for selecting a subset of features in the point cloud data
Cropping extent Opcional	FILTER_EXTENT	[extent]	A map extent for selecting a subset of features in the point cloud data Available methods are: Calculate from layer…: uses extent of a layer loaded in the current project Calculate from layout map…: uses extent of a layout map item in the active project Calculate from bookmark…: uses extent of a saved bookmark Use map canvas extent Draw on canvas: click and drag a rectangle delimiting the area to take into account Enter the coordinates as xmin, xmax, ymin, ymax

Resultados

Label	Nome	Type	Descrição
Thinned (by radius)	OUTPUT	[point cloud]	Output point cloud layer with reduced points.

Python code

Algorithm ID: pdal:thinbyradius

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Usando os algoritmos do processamento a partir da consola for details on how to run processing algorithms from the Python console.

28.1.13.9. Thin (by skipping points)

Creates a thinned version of the point cloud by keeping only every N-th point (reduces the number of points by skipping nearby points).

Veja também

Thin (by sampling radius)

Parâmetros

Basic parameters

Label	Nome	Type	Descrição
Input layer	INPUT	[point cloud]	Input point cloud layer to create a thinned version from
Number of points to skip	POINTS_NUMBER	[number] Default: 1	Keep only every N-th point in the input layer
Thinned (by decimation)	OUTPUT	[point cloud] Default: [Save to temporary file]	Specify the output point cloud with reduced points. One of: Save to a Temporary File Save to File…

Advanced parameters

Label	Nome	Type	Descrição
Filter expression Opcional	FILTER_EXPRESSION	[expression]	A PDAL expression for selecting a subset of features in the point cloud data
Cropping extent Opcional	FILTER_EXTENT	[extent]	A map extent for selecting a subset of features in the point cloud data Available methods are: Calculate from layer…: uses extent of a layer loaded in the current project Calculate from layout map…: uses extent of a layout map item in the active project Calculate from bookmark…: uses extent of a saved bookmark Use map canvas extent Draw on canvas: click and drag a rectangle delimiting the area to take into account Enter the coordinates as xmin, xmax, ymin, ymax

Resultados

Label	Nome	Type	Descrição
Thinned (by decimation)	OUTPUT	[point cloud]	Output point cloud layer with reduced points.

Python code

Algorithm ID: pdal:thinbydecimate

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Usando os algoritmos do processamento a partir da consola for details on how to run processing algorithms from the Python console.

28.1.13.10. Tile

Creates tiles from input point cloud files, recommended for best performance (in display or analysis) with such datasets in QGIS.

Veja também

Build virtual point cloud (VPC), Create COPC

Parâmetros

Basic parameters

Label	Nome	Type	Descrição
Input layers	LAYERS	[point cloud] [list]	Input point cloud layers to create tiles from
Tile length	LENGTH	[number] Default: 1000.0	Size of the edge of each generated tile
Output directory	OUTPUT	[folder] Default: [Save to temporary folder]	Specify the folder to store the generated tiles. One of: Save to a Temporary Directory Save to Directory

Advanced parameters

Label	Nome	Type	Descrição
Assign CRS Opcional	CRS	[crs]	The CRS to apply to the layer

Resultados

Label	Nome	Type	Descrição
Output directory	OUTPUT	[folder]	Output folder containing the tiles generated from input files.

Python code

Algorithm ID: pdal:tile

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Usando os algoritmos do processamento a partir da consola for details on how to run processing algorithms from the Python console.