Desktop Help 10.0 - LAS To Multipoint (3D Analyst)

Summary

This tool imports one or more files in LAS format, the industry standard for lidar data, into a new multipoint feature class. Supported LAS file format versions are 1.0, 1.1, and 1.2.

Usage

LAS points can be classified into a number of categories including bare earth or ground, top of canopy, and water. The different classes are defined using numeric integer codes. Unfortunately, the LAS 1.0 specification does not have a predefined classification scheme, nor do the files summarize what, if any, class codes are used by the points. You need to be given this information from the data provider.

If you are working with the LAS 1.1 or 1.2 specification, refer to the predefined classification schemes defined by American Society for Photogrammetry and Remote Sensing (ASPRS) for the desired data category. The following table lists the LAS class codes based on LAS version 1.2 defined by ASPRS.

To import predefined LAS points from the LAS file or files, you can specify them in the Input Class Codes parameter.

ASPRS Standard LiDAR Point Classes

Classification Value	Meaning
0	Created, never classified
1	Unclassified
2	Ground
3	Low Vegetation
4	Medium Vegetation
5	High Vegetation
6	Building
7	Low Points (noise)
8	Model Key-Points (mass points)
9	Water
10	Reserved for ASPRS Definition
11	Reserved for ASPRS Definition
12	Overlap Points
13-31	Reserved fro ASPRS Definition

Supported LAS versions are 1.0, 1.1, and 1.2.
If you are not interested in importing points based on their return number, or if all returns specified in the file or files are set to 0 because the points have been filtered or classified, select ANY_RETURN.
When loading multiple LAS attributes into an Oracle database, you'll need to make sure all DBTUNE keywords for parameter attribute_binary are set to use binary large objects (BLOBs), not LONGRAW. This is because LAS attributes are loaded as BLOBs, and Oracle does not support multiple BLOBs in LONGRAW tables. See your Oracle database administrator for assistance.

Syntax

LASToMultipoint_3d (input, out_feature_class, average_point_spacing, {class_code}, {return}, {attribute}, {input_coordinate_system}, {file_suffix}, {z_factor})

Parameter	Explanation	Data Type
input	One or more files or folders with data in the LAS version 1.0, 1.1, and 1.2 format. The LAS format is the industry standard for lidar data.	Folder; File
out_feature_class	The newly created multipoint feature class to which lidar points are added.	Feature Class
average_point_spacing	The average 2D distance between points in the input file or files. This can be an approximation. If areas have been sampled at different densities, specify the smaller spacing. The value needs to be provided in the projection units of the output coordinate system.	Double
class_code (Optional)	Numeric classification codes to use as a query filter. The default is no filter.	Long
return (Optional)	The return values used as a query filter. Valid return values are 1-5, LAST_RETURNS, and ANY_RETURNS. The default is ANY_RETURNS.	String
attribute (Optional)	One or more LAS attributes to load and store and optionally the field names to use. The default is none. Supported attribute keywords are INTENSITY, RETURN_NUMBER, NUMBER_OF_RETURNS, SCAN_DIRECTION_FLAG, EDGE_OF_FLIGHTLINE, CLASSIFICATION, SCAN_ANGLE_RANK, FILE_MARKER, USER_BIT_FIELD, and GPS_TIME.	String
input_coordinate_system (Optional)	The coordinate system of the input LAS file. This defaults to that specified in the LAS file. If for some reason it's not defined in the file but you know what it is, provide it here.	Coordinate system
file_suffix (Optional)	The suffix of the files to import when a folder is specified on input.	String
z_factor (Optional)	Specifies a factor by which to multiply the surface heights. Used to convert z units to x and y units.	Double

Code Sample

LAS To Multipoint Example 1 (Python window)

The following Python Window script demonstrates how to use the LAS To Multipoint function in immediate mode.

import arcpy
from arcpy import env

arcpy.CheckOutExtension("3D")
env.workspace = "C:/data"
arcpy.LASToMultipoint_3d("001.las", "Test.gdb/feature_dataset/sample_1", 1.5, 
                        "2", "ANY_RETURNS", "INTENSITY", "Coordinate Systems"\
                        "/Projected Coordinate Systems/UTM/NAD 1983/NAD 1983 "\
                        "UTM Zone 17N.prj", "las", 1)

LAS To Multipoint Example 2 (stand-alone script)

The following Python script demonstrates how to use the LAS To Multipoint function in a stand-alone script.

'''****************************************************************************
Name: Define Data Boundary of LAS File
Description: This script demonstrates how to delineate data boundaries of 
             LAS files with irregularly clustered points. It is intended for 
             use as a script tool with one input LAS file.
****************************************************************************'''
# Import system modules
import arcpy
import exceptions, sys, traceback

# Set local variables
inLas = arcpy.GetParameterAsText(0) #input LAS file
ptSpacing = arcpy.GetParameterAsText(1) # LAS point spacing
classCode = arcpy.GetParameterAsText(2) # List of integers
returnValue = arcpy.GetParameterAsText(3) # List of strings
outTin = arcpy.GetParameterAsText(4) # TIN created to delineate data area
outBoundary = arcpy.GetParameterAsText(5) # Polygon boundary file

try:
    arcpy.CheckOutExtension("3D")
    # Execute LASToMultipoint
    arcpy.AddMessage("Creating multipoint features from LAS...")
    lasMP = arcpy.CreateUniqueName('lasMultipoint', 'in_memory')
    arcpy.ddd.LASToMultipoint(inLas, LasMP, ptSpacing, class_code, 
                             "ANY_RETURNS", "", sr, inFormat, zfactor)
    # Execute CreateTin
    arcpy.AddMessage("Creating TIN dataset...")
    arcpy.ddd.CreateTin(outTin, sr, "{0} Shape.Z masspoints"\
                       .format(lasMP), "Delaunay")
    # Execute CopyTin
    arcpy.AddMessage("Copying TIN to delineate data boundary...")
    arcpy.ddd.CopyTin(outTin, "{0}_copy".format(outTin))
    # Execute DelineateTinDataArea
    arcpy.AddMessage("Delineating TIN boundary...")
    maxEdge = ptSpacing * 4
    arcpy.ddd.DelineateTinDataArea(outTin, maxEdge, "PERIMETER_ONLY")
    # Execute TinDomain
    arcpy.AddMessage("Exporting data area to polygon boundary...")
    arcpy.ddd.TinDomain(outTin, outBoundary, "POLYGON")
    arcpy.AddMessage("Finished")
    arcpy.CheckInExtension("3D")
        
except arcpy.ExecuteError:
    print arcpy.GetMessages()
except:
    # Get the traceback object
    tb = sys.exc_info()[2]
    tbinfo = traceback.format_tb(tb)[0]
    # Concatenate error information into message string
    pymsg = 'PYTHON ERRORS:\nTraceback info:\n{0}\nError Info:\n{1}'\
          .format(tbinfo, str(sys.exc_info()[1]))
    msgs = 'ArcPy ERRORS:\n {0}\n'.format(arcpy.GetMessages(2))
    # Return python error messages for script tool or Python Window
    arcpy.AddError(pymsg)
    arcpy.AddError(msgs)

Environments

Current Workspace, Output XY Domain, Output Z Domain, Output Coordinate System, Extent, Scratch Workspace

Licensing Information

ArcView: Requires 3D Analyst

ArcEditor: Requires 3D Analyst

ArcInfo: Requires 3D Analyst

6/10/2013

LAS To Multipoint (3D Analyst)