Create LAS Dataset (Data Management)

Summary

Creates a LAS dataset referencing one or more *.las, *.zlas, and *.laz files and surface constraint features.

Illustration

Usage

• The LAS dataset provides a way to visualize, manage, and analyze collections of point cloud data stored in uncompressed LAS files (*.las) and compressed variants (*.zlas and *.laz). The LAS dataset references the input files where they reside and supports working with a large collection of separate files through a single access point that can optimize the rendering experience. Compressed files typically use approximately 30 percent of the storage size of uncompressed files, making them a suitable alternative for managing large collections of data and archival storage. You can edit the class codes of uncompressed .las files and .zlas files. When considering which file format to use, evaluate the formats by the applications in which they will be used.

  Learn more about the data types supported by the LAS dataset

  ZLAS files can be created with any tool that creates .las files, including: Convert LAS, Extract LAS, Thin LAS, Tile LAS, and Project LAS. LAZ files can be created with the Convert LAS tool.

• Surface constraint features can be used to enforce feature-derived elevation values that represent surface characteristics in the LAS dataset.

• Each LAS file (*.las, *.zlas, or .laz) that will be added to the LAS dataset is examined to determine if its file structure meets the ASPRS LAS format specifications. Files that are improperly created or corrupted will fail to load. If this occurs, use the Esri CheckLAS application to evaluate the file.

• The ASPRS specifications for a .las file require the file to have spatial reference information. If this information is missing or improperly defined, the file will have an unknown spatial reference, which will cause it to render in the coordinate system of the map. If the correct spatial reference is known, use the Define Projection tool or the Create LAS Dataset tool with the Create PRJ For LAS Files set to All LAS File or Files with Missing Spatial References.

  Learn more about how LAS coordinate system information is stored and modified

• The class code labels provided in the LAS dataset's layer and catalog properties reflect the class designations outlined in the ASPRS LAS 1.4 specifications. This classification scheme is oriented for aerial lidar surveys and is comprised of the following:

  • Classes associated with predefined objects, for example, 2 represents ground
  • Classes whose values are not defined but reserved for later use by the ASPRS
  • Classes that can be allocated to any other object
  The LAS dataset layer's point filters, interactive editing options, and default symbology labels reflect the LAS format specification's class code labels.

  Learn more about lidar point classification.

• If the LAS standard is applicable for the data but the class codes do not conform, consider modifying the class designations to match the ASPRS LAS 1.4 standards to ensure that the data will be interpreted in a consistent manner. Since LAS format 1.0 files did not require any classification standard, data vendors may have applied classification codes to objects that did not match the standard that was introduced in the more recent LAS formats. If the class code values in the data are not consistent with the LAS standard, use the Change LAS Class Codes tool to align the value with the latest ASPRS classification scheme.

• In the Geoprocessing pane, a folder can also be specified as an input by selecting the folder in File Explorer and dragging it onto the parameter's input box.

Parameters

Dialog

Label	Explanation	Data Type
Input LAS Files	The LAS format files (*.las, .zlas, and *.laz), LAS datasets (*.lasd), and folders containing such files that will be added to the output LAS dataset. When a LAS dataset is provided, all of its referenced LAS format files with valid paths will be added to the output. In the Geoprocessing pane, a folder can also be specified as an input by selecting the folder in File Explorer and dragging it onto the parameter's input box.	LAS Dataset Layer; File; Folder
Output LAS Dataset	The LAS dataset that will be created.	LAS Dataset
Include subfolders (Optional)	Specifies whether LAS format files (.las, .zlas, and .laz) residing in the subdirectories of an input folder will be added to the LAS dataset. This parameter only applies when the Input Files parameter value contains a folder. Unchecked—Only LAS format files residing in an input folder will be added to the LAS dataset. This is the default. Checked—All LAS format files residing in the subdirectories of an input folder will be added to the LAS dataset.	Boolean
Surface Constraints (Optional)	The features that will contribute to the definition of the triangulated surface generated from the LAS dataset. Input Features—The features with geometry that will be incorporated into the LAS dataset's triangulated surface. Height Field—The feature's elevation source can be derived from any numeric field in the feature's attribute table or the geometry by selecting Shape.Z. If no height is necessary, specify the keyword <None> to create z-less features with elevation that will be interpolated from the surface. Type—Defines the feature's role in the triangulated surface generated from the LAS dataset. Options with hard or soft designation refer to whether the feature edges represent distinct breaks in slope or a gradual change. Surface Feature Type—The surface feature type that defines how the feature geometry will be incorporated into the triangulation for the surface. Options with hard or soft designation refer to whether the feature edges represent distinct breaks in slope or a gradual change. anchorpoints—Elevation points that will not be thinned away. This option is only available for single-point feature geometry. hardline or softline—Breaklines that enforce a height value. hardclip or softclip—Polygon dataset that defines the boundary of the LAS dataset. harderase or softerase—Polygon dataset that defines holes in the LAS dataset. hardreplace or softreplace—Polygon dataset that defines areas of constant height.	Value Table
Coordinate System (Optional)	The spatial reference that will be assigned to the output LAS dataset. The default coordinate system will match the spatial reference of the first input file. When a coordinate system that differs from the input files is specified, it will result in the input files being reprojected to the LAS dataset's coordinate system when processed in subsequent operations. If the input files do not have a spatial reference, the coordinate system will default to unknown. When the coordinate system for files with no spatial reference is known, the correct coordinate system can be defined for the input files by selecting it in this parameter and setting the Define Projection for LAS Files parameter to Files with Unknown Spatial Reference.	Coordinate System
Compute Statistics (Optional)	Specifies whether statistics and a spatial index will be computed for the input files. The presence of statistics allows the LAS dataset layer's filtering and symbology options to only show LAS attribute values that exist in the .las files. A .lasx auxiliary file is created for each .las file. Unchecked—Statistics will not be computed. This is the default. Checked—Statistics will be computed.	Boolean
Store Relative Paths (Optional)	Specifies whether the source data referenced by the LAS dataset will use relative or absolute paths. Relative paths may be convenient when the LAS dataset and its associated data will be relocated in the file system using the same relative location. Unchecked—Absolute paths will be used for the data referenced by the LAS dataset. This is the default. Checked—Relative paths will be used for the data referenced by the LAS dataset.	Boolean
Define Projection For LAS Files	Specifies whether the input *.las, .zlas, or *.laz files will have their coordinate system defined by a .prj file that is created for them using the spatial reference in the Coordinate System parameter. The .prj file will override any spatial reference information stored in the LAS format files being added to the LAS dataset. No Files—None of the input *.las, .zlas, or *.laz files will have a .prj created. This is the default. Files with Unknown Spatial Reference—The input *.las, .zlas, or *.laz files that do not have a spatial reference will have a .prj created. All Files—All input *.las, .zlas, or *.laz files will have a .prj created for them.	String
Processing Extent (Optional)	The processing extent that will be used to filter the files being added to the LAS dataset. Any input file that is outside this extent will be excluded from the resulting LAS dataset. Files that partially overlap with the extent can be excluded if the Add only entirely contained files parameter is checked.	Extent
Processing Boundary (Optional)	The polygon boundary feature that will be used to filter the files being added to the LAS dataset. Any input file that is outside this boundary will be excluded from the resulting LAS dataset. Files that partially overlap the boundary will be excluded if the Add only entirely contained files parameter is checked.	Feature Layer
Add only entirely contained files (Optional)	Specifies whether the input files being added to the LAS dataset must be fully or partially contained by the processing extent and processing boundary. Unchecked—All files that intersect the processing extent, processing boundary, or the intersection of both will be added to the LAS dataset. This is the default. Checked—Only files that are entirely contained by the processing extent, processing boundary, or the intersection of both will be added to the LAS dataset.	Boolean

Python

arcpy.management.CreateLasDataset(input, out_las_dataset, {folder_recursion}, {in_surface_constraints}, {spatial_reference}, {compute_stats}, {relative_paths}, create_las_prj, {extent}, {boundary}, {add_only_contained_files})

Name	Explanation	Data Type
input [input,...]	The LAS format files (*.las, .zlas, and *.laz), LAS datasets (*.lasd), and folders containing such files that will be added to the output LAS dataset. When a LAS dataset is provided, all of its referenced LAS format files with valid paths will be added to the output.	LAS Dataset Layer; File; Folder
out_las_dataset	The LAS dataset that will be created.	LAS Dataset
folder_recursion (Optional)	Specifies whether LAS format files (.las, .zlas, and .laz) residing in the subdirectories of an input folder will be added to the LAS dataset. NO_RECURSION—Only LAS format files residing in an input folder will be added to the LAS dataset. This is the default. RECURSION—All LAS format files residing in the subdirectories of an input folder will be added to the LAS dataset.	Boolean
in_surface_constraints [[in_feature_class, height_field, SF_type],...] (Optional)	The features that will be referenced by the LAS dataset when generating a triangulated surface. Each feature must have the following properties defined: in_feature_class—The feature to be referenced by the LAS dataset. height_field—Any numeric field in the feature's attribute table can be used to define the height source. If the feature's geometry contains z-values, it can be selected by specifying Shape.Z. If no height is necessary, specify the keyword <None> to create z-less features with elevation that will be interpolated from the surface. SF_type—The surface feature type that defines how the feature geometry will be incorporated into the triangulation for the surface. Options with hard or soft designation refer to whether the feature edges represent distinct breaks in slope or a gradual change. anchorpoints—Elevation points that will not be thinned away. This option is only available for single-point feature geometry. hardline or softline—Breaklines that enforce a height value. hardclip or softclip—Polygon dataset that defines the boundary of the LAS dataset. harderase or softerase—Polygon dataset that defines holes in the LAS dataset. hardreplace or softreplace—Polygon dataset that defines areas of constant height.	Value Table
spatial_reference (Optional)	The spatial reference that will be assigned to the output LAS dataset. The default coordinate system will match the spatial reference of the first input file. When a coordinate system that differs from the input files is specified, it will result in the input files being reprojected to the LAS dataset's coordinate system when processed in subsequent operations. If the input files do not have a spatial reference, the coordinate system will default to unknown. When the coordinate system for files with no spatial reference is known, the correct coordinate system can be defined for the input files by selecting it in this parameter and setting the create_las_prj parameter to FILES_MISSING_PROJECTION.	Coordinate System
compute_stats (Optional)	Specifies whether statistics and a spatial index will be computed for the input files. The presence of statistics allows the LAS dataset layer's filtering and symbology options to only show LAS attribute values that exist in the .las files. A .lasx auxiliary file is created for each .las file. COMPUTE_STATS—Statistics will be computed. NO_COMPUTE_STATS—Statistics will not be computed. This is the default.	Boolean
relative_paths (Optional)	Specifies whether the source data referenced by the LAS dataset will use relative or absolute paths. Relative paths may be convenient when the LAS dataset and its associated data will be relocated in the file system using the same relative location. ABSOLUTE_PATHS—Absolute paths will be used for the data referenced by the LAS dataset. This is the default. RELATIVE_PATHS—Relative paths will be used for the data referenced by the LAS dataset.	Boolean
create_las_prj	Specifies whether the input *.las, .zlas, or *.laz files will have their coordinate system defined by a .prj file that is created for them using the spatial reference in the spatial_reference parameter. The .prj file will override any spatial reference information stored in the input LAS format files being added to the LAS dataset. NO_FILES—None of the input *.las, .zlas, or *.laz files will have a .prj created. This is the default. FILES_MISSING_PROJECTION—The input *.las, .zlas, or *.laz files that do not have a spatial reference will have a .prj created. ALL_FILES—All input *.las, .zlas, or *.laz files will have a .prj created for them.	String
extent (Optional)	The processing extent that will be used to filter the files being added to the LAS dataset. Any input file that is outside this extent will be excluded from the resulting LAS dataset. Files that partially overlap with the extent can be excluded if the add_only_contained_files parameter is set to INTERSECTED_FILES.	Extent
boundary (Optional)	The polygon boundary feature that will be used to filter the files being added to the LAS dataset. Any input file that is outside this boundary will be excluded from the resulting LAS dataset. Files that partially overlap the boundary will be excluded if the add_only_contained_files parameter is set to INTERSECTED_FILES.	Feature Layer
add_only_contained_files (Optional)	Specifies whether the input files being added to the LAS dataset must be fully or partially contained by the processing extent and processing boundary. INTERSECTED_FILES—All files that intersect the processing extent and processing boundary will be added to the LAS dataset. This is the default. CONTAINED_FILES—Only files that are entirely contained by the processing extent and processing boundary will be added to the LAS dataset.	Boolean

Code sample

CreateLasDataset example 1 (Python window)

The following sample demonstrates the use of this tool in the Python window:

import arcpy

arcpy.env.workspace = "C:/data"
arcpy.management.CreateLasDataset("folder_a; folder_b/5S4E.las", 
                                "test.lasd", "RECURSION",
                                "LA/boundary.shp <None> Softclip;"\
                                "LA/ridges.shp Elevation hardline", "", 
                                "COMPUTE_STATS", "RELATIVE_PATHS")

CreateLasDataset example 2 (stand-alone script)

The following sample demonstrates the use of this tool in a stand-alone Python script:

'''*********************************************************************
Name: Export Elevation Raster from Ground LAS Measurements
Description: This script demonstrates how to export
             ground measurements from LAS files to a raster using a
             LAS dataset. This sample is designed to be used as a script
             tool.
*********************************************************************'''
# Import system modules
import arcpy

try:
    # Set Local Variables
    inLas = arcpy.GetParameterAsText(0)
    recursion = arcpy.GetParameterAsText(1)
    surfCons = arcpy.GetParameterAsText(2)
    classCode = arcpy.GetParameterAsText(3)
    returnValue = arcpy.GetParameterAsText(4)
    spatialRef = arcpy.GetParameterAsText(5)
    lasD = arcpy.GetParameterAsText(6)
    outRaster = arcpy.GetParameterAsText(7)
    cellSize = arcpy.GetParameter(8)
    zFactor = arcpy.GetParameter(9)

    # Execute CreateLasDataset
    arcpy.management.CreateLasDataset(inLas, lasD, recursion, surfCons, sr)
    # Execute MakeLasDatasetLayer
    lasLyr = arcpy.CreateUniqueName('Baltimore')
    arcpy.management.MakeLasDatasetLayer(lasD, lasLyr, classCode, returnValue)
    # Execute LasDatasetToRaster
    arcpy.conversion.LasDatasetToRaster(lasLyr, outRaster, 'ELEVATION',
                              'TRIANGULATION LINEAR WINDOW_SIZE 10', 'FLOAT',
                              'CELLSIZE', cellSize, zFactor)
    print(arcpy.GetMessages())

except arcpy.ExecuteError:
    print(arcpy.GetMessages())

except Exception as err:
    print(err.args[0])

finally:
    arcpy.management.Delete(lasLyr)

Environments

Current Workspace, Output Coordinate System

Licensing information

• Basic: Requires 3D Analyst or Spatial Analyst
• Standard: Yes
• Advanced: Yes