Change Terrain Reference Scale (3D Analyst)
Summary
Changes the reference scale associated with a terrain pyramid level.
Usage
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Consider changing a terrain pyramid's reference scale if you experience undesirable draw speed performance or require greater densification of data points in the pyramid's display scale range.
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It may also be necessary to add or remove a pyramid level when changing the resolution of an existing one, which can be done by using Add Terrain Pyramid or Remove Terrain Pyramid.
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When used in an SDE database, the input terrain cannot be registered as versioned.
Syntax
| Parameter | Explanation | Data Type |
in_terrain |
The input terrain dataset. | Terrain Layer |
old_refscale |
The reference scale of an existing pyramid level. | Long |
new_refscale |
The new reference scale for the pyramid level. | Long |
Code Sample
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.ChangeTerrainReferenceScale_3d('terrain.gdb/terrainFDS/terrain1',
1000, 2000)
The following sample demonstrates the use of this tool in a stand-alone Python script:
'''****************************************************************************
Name: Update Terrain
Description: This script demonstrates how to update a terrain dataset
with new elevation measurements obtained from Lidar by
importing LAS files to multipoint features, then appending the
new points to another multipoint feature that participates in a
terrain. The terrain's pyramids are modified to optimize its
draw speed.
****************************************************************************'''
# Import system modules
import arcpy
from arcpy import env
import exceptions, sys, traceback
try:
arcpy.CheckOutExtension("3D")
# Set environment settings
env.workspace = "C:/data"
# Set Variables
inTerrain = "sample.gdb/featuredataset/terrain"
currentPts = "existing_points"
lasFiles = ['las/NE_Philly.las',
'las/NW_Philly.las']
newPts = 'in_memory/update_pts'
# Define spatial reference of LAS files using factory code
# for NAD_1983_StatePlane_Pennsylvania_South
lasSR = arcpy.SpatialReference()
lasSR.factoryCode = 2272
lasSR.create()
arcpy.AddMessage("Converting LAS files to multipoint features...")
arcpy.ddd.LASToMultipoint(lasFiles, newPts, 1.5, 2, 1,
'INTENSITY', lasSR)
arcpy.AddMessage("Appending LAS points to {0}..."\
.format(currentPts))
arcpy.AppendTerrainPoints_3d(inTerrain, currentPts, newPts)
arcpy.AddMessage("Changing terrain pyramid reference scales...")
arcpy.ddd.ChangeTerrainReferenceScale(inTerrain, 1000, 500)
arcpy.ddd.ChangeTerrainReferenceScale(inTerrain, 2500, 2000)
arcpy.AddMessage("Adding terrain pyramid level...")
arcpy.ddd.AddTerrainPyramidLevel(inTerrain, "", "4 4500")
arcpy.AddMessage("Changing pyramid resolution bounds for breaklines...")
arcpy.ChangeTerrainResolutionBounds_3d(inTerrain, "breaklines", 5, 4)
arcpy.AddMessage("Building terrain...")
arcpy.ddd.BuildTerrain(inTerrain)
arcpy.AddMessage("Completed updates.")
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")