Build Terrain

Summary

Performs tasks required for analyzing and displaying a terrain dataset.

Usage

• This tool will need to be used after initially defining the features that participate in a terrain, making subsequent modifications to the features that participate in the terrain, or modifying the terrain pyramid definition.

• It is more efficient to make a collection of edits followed by one build rather than running a build after each individual edit.

Syntax

BuildTerrain_3d (in_terrain, {update_extent})

Parameter	Explanation	Data Type
in_terrain	The terrain dataset to process.	Terrain Layer
update_extent (Optional)	Recalculates the data extent of a window-size-based terrain dataset when the data area has been reduced through editing. It is not needed if the data extent has increased or if the terrain dataset is z-tolerance based. It will scan through all the terrain data to determine the new extent. NO_UPDATE_EXTENT — The extent of the terrain dataset will not be recalculated. This is the default. UPDATE_EXTENT — The extent of the terrain dataset will be recalculated.	String

Code Sample

BuildTerrain example 1 (Python window)

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

import arcpy
from arcpy import env

arcpy.CheckOutExtension('3D')
env.workspace = 'C:/data'
arcpy.BuildTerrain_3d('test.gdb/featuredataset/terrain')

BuildTerrain example 2 (stand-alone script)

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

"""****************************************************************************
Name: Create Terrain from TIN
Description: This script demonstrates how to create a terrain dataset using
             features extracted from a TIN. It is particularly useful in 
             situations where the source data used in the TIN is not available,
             and the amount of data stored in the TIN proves to be too large 
             for the TIN. The terrain's scalability will allow improved
             display performance and faster analysis. The script is designed 
             to work as a script tool with 5 input arguments.
****************************************************************************"""
# Import system modules
import arcpy
import exceptions, sys, traceback
from arcpy import env

# Set local variables
tin = arcpy.GetParameterAsText(0) # TIN used to create terrain
gdbLocation = arcpy.GetParameterAsText(1) # Folder that will store terran GDB
gdbName = arcpy.GetParameterAsText(2) # Name of terrain GDB
fdName = arcpy.GetParameterAsText(3) # Name of feature dataset
terrainName = arcpy.GetParameterAsText(4) # Name of terrain

try:
    arcpy.CheckOutExtension("3D")
    # Create the file gdb that will store the feature dataset
    arcpy.management.CreateFileGDB(gdbLocation, gdbName)
    gdb = '{0}/{1}'.format(gdbLocation, gdbName)
    # Obtain spatial reference from TIN
    SR = arcpy.Describe(tin).spatialReference
    # Create the feature dataset that will store the terrain
    arcpy.management.CreateFeatureDataset(gdb, fdName, SR)
    fd = '{0}/{1}'.format(gdb, fdName)
    # Export TIN elements to feature classes for terrain
    arcpy.AddMessage("Exporting TIN footprint to define terrain boundary...")
    boundary = "{0}/boundary".format(fd)
    # Execute TinDomain
    arcpy.ddd.TinDomain(tin, tinDomain, 'POLYGON')
    arcpy.AddMessage("Exporting TIN breaklines...")
    breaklines = "{0}/breaklines".format(fd)
    # Execute TinLine
    arcpy.ddd.TinLine(tin, breaklines, "Code")
    arcpy.AddMessage("Exporting TIN nodes...")
    masspoints = "{0}/masspoints".format(fd)
    # Execute TinNode
    arcpy.ddd.TinNode(sourceTIN, TIN_nodes)
    arcpy.AddMessage("Creating terrain dataset...")
    terrain = "terrain_from_tin"
    # Execute CreateTerrain
    arcpy.ddd.CreateTerrain(fd, terrainName, 10, 50000, "", 
                            "WINDOWSIZE", "ZMEAN", "NONE", 1)
    arcpy.AddMessage("Adding terrain pyramid levels...")
    terrain = "{0}/{1}".format(fd, terrainName)
    pyramids = ["20 5000", "25 10000", "35 25000", "50 50000"]
    # Execute AddTerrainPyramidLevel
    arcpy.ddd.AddTerrainPyramidLevel(terrain, "", pyramids)
    arcpy.AddMessage("Adding features to terrain...")
    inFeatures = "{0} Shape softclip 1 0 10 true false boundary_embed <None> "\
             "false; {1} Shape masspoints 1 0 50 true false points_embed "\
             "<None> false; {2} Shape softline 1 0 25 false false lines_embed "\
             "<None> false".format(boundary, masspoints, breaklines)
    # Execute AddFeatureClassToTerrain
    arcpy.ddd.AddFeatureClassToTerrain(terrain, inFeatures) 
    arcpy.AddMessage("Building terrain...")
    # Execute BuildTerrain
    arcpy.ddd.BuildTerrain(terrain, "NO_UPDATE_EXTENT")
    arcpy.GetMessages()

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)
finally:
    arcpy.CheckInExtension("3D")

Environments

• Current Workspace
• Extent
• Auto Commit

Licensing Information

• ArcGIS for Desktop Basic: Requires 3D Analyst
• ArcGIS for Desktop Standard: Requires 3D Analyst
• ArcGIS for Desktop Advanced: Requires 3D Analyst

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