Create Terrain (3D Analyst)
Resumen
Creates a new terrain dataset.
Uso
The terrain must reside in a feature dataset.
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The Average Point Spacing parameter should be based on the data that will be used in the terrain. While this value does not need to be exact, it should represent a good approximation. If the data has been gathered at significantly different densities from one location to another, give more weight to the smaller spacing in determining this value.
The point spacing is used to determine the terrain tile size, which is used to optimize data analysis and display performance. Each tile is approximated to contain no more than 200,000 source elevation points.
Use Add Terrain Pyramid Level, and Add Feature Class To Terrain, followed by Build Terrain to complete the terrain definition and construct a usable terrain.
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Geoprocessing tools for terrain construction are geared toward data automation procedures in Python scripts and ModelBuilder. Consider using the Terrain Wizard in ArcCatalog or the Catalog window for interactively creating a new terrain. To access the Terrain Wizard, right-click a feature dataset and click New > Terrain.
Sintaxis
Parámetro | Explicación | Tipo de datos |
in_feature_dataset |
The feature dataset where the terrain dataset will be created. | Feature Dataset |
out_terrain_name |
The output terrain dataset. | String |
average_point_spacing |
The average, or nominal, horizontal distance between points for the data being used to build the terrain. Data collected for photogrammetric, lidar, and sonar surveys typically have a known spacing. This is the value that should be used. If you're unsure of the spacing you should go back and check the data rather than guess. The spacing is given in the horizontal units of the feature dataset's coordinate system. | Double |
max_overview_size (Opcional) |
The terrain overview is the coarsest representation of the terrain dataset, and is similar to the image thumbnail concept. The maximum size represents the upper limit of the number of measurement points sampled to create the overview. | Long |
config_keyword (Opcional) |
Configuration keyword for ArcSDE. A configuration keyword is used to optimize database storage and is typically configured by the database administrator. | String |
pyramid_type (Opcional) |
The point thinning method used to construct the terrain pyramids.
| String |
windowsize_method (Opcional) |
The criterion used for selecting points in the area defined by the window size. This parameter is only applicable when WINDOWSIZE is specified in the Pyramid Type parameter.
| String |
secondary_thinning_method (Opcional) |
Specifies additional thinning options to reduce the number of points used over flat areas when Window Size pyramids are being used. An area is considered flat if the heights of points in an area are within the value supplied for the Secondary Thinning Threshold parameter. Its effect is more evident at higher-resolution pyramid levels, since smaller areas are more likely to be flat than larger areas.
| String |
secondary_thinning_threshold (Opcional) |
The vertical threshold used to activate secondary thinning with the Window Size filter. The value should be set equal to or larger than the vertical accuracy of the data. | Double |
Ejemplo de código
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.CreateTerrain_3d('source.gdb/Redlands', 'Redlands_terrain', 5, 50000, '', 'WINDOWSIZE', 'ZMIN', 'NONE', 1)
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")