Surface Contour (3D Analyst)
Summary
Creates a feature class containing a set of contours generated from a terrain dataset or TIN surface. The output feature class is 2D and contains an attribute with contour values.
Illustration
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Usage
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Use the interval and base contour options to tailor the extent and resolution of the output feature class.
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Use the out contour field data to convert the feature class to 3D.
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In certain instances the last valid contour line may not be produced when creating contours using TIN surfaces. This is an algorithmic limitation common to computer contouring software. To ensure that all valid contours are generated, add a very small negative value to the Base Contour field to slightly shift the data.
The Z factor parameter only affects results for rasters and TINs, not terrain datasets. When working with terrain datasets you can specify a contour interval that has the z factor built in to it. For example, if you want a one foot contour interval and your terrain dataset surface is in meters, specify a contour interval of 0.3048. You can also convert the terrain dataset to a raster or TIN using either the Terrain To Raster or Terrain To TIN geoprocessing tools.
Syntax
| Parameter | Explanation | Data Type |
in_surface |
The input terrain dataset or TIN surface. | Tin Layer; Terrain Layer |
out_feature_class |
The output feature class. | Feature Class |
interval |
The interval between the contours. | Double |
base_contour (Optional) |
Along with the index interval, the base height is used to determine what contours are produced. The base height is a starting point from which the index interval is either added or subtracted. By default, the base contour is 0.0. | Double |
contour_field (Optional) |
The field containing contour values. | String |
contour_field_precision (Optional) |
The precision of the contour field. Zero specifies an integer, and the numbers 1–9 indicate how many decimal places the field will contain. By default, the field will be an integer (0). | Long |
index_interval (Optional) |
The difference, in Z units, between index contours. The value specified should be evenly divisible by the contour interval. Typically, it’s five times greater. Use of this parameter adds an attribute field to the output feature class that’s used to differentiate index contours from regular contours. | Double |
index_interval_field (Optional) |
The name of the field used to record whether a contour is a regular or an index contour. By default, the value is ‘Index’. | String |
z_factor (Optional) |
Specifies a factor by which to multiply the surface heights. Used to convert z units to x and y units. The Z factor parameter only affects results for rasters and TINs, not terrain datasets. | Double |
pyramid_level_resolution (Optional) |
The pyramid level resolution of the terrain dataset to use for interpolation. The default is 0, full resolution. | Double |
Code Sample
The following Python Window script demonstrates how to use the Surface Contour function in immediate mode.
import arcpy
from arcpy import env
arcpy.CheckOutExtension("3D")
env.workspace = "C:/data"
arcpy.SurfaceContour_3d("sample.gdb/featuredataset/terrain", "contour.shp", 10)
The following Python script demonstrates how to use the Surface Contour function in a stand-alone script.
'''****************************************************************************
Name: SurfaceContour Example
Description: This script demonstrates how to use the
SurfaceContour tool.
****************************************************************************'''
# Import system modules
import arcpy
from arcpy import env
# Obtain a license for the ArcGIS 3D Analyst extension
arcpy.CheckOutExtension("3D")
# Set environment settings
env.workspace = "C:/data"
# Set Local Variables
inSurface = "sample.gdb/featuredataset/terrain"
outContour = arcpy.CreateUniqueName("contour.shp")
#Execute SurfaceContour
arcpy.SurfaceContour_3d(inSurface, outContour, 10)
del inSurface, outContour, arcpy