ArcMap

Interpolate Shape

Summary

Creates 3D features by interpolating z-values from a surface.

Learn more about how Interpolate Shape works

Illustration

Interpolate Shape illustration

Usage

  • When using natural neighbors interpolation, consider specifying a sampling distance that's equal to or above half of the average point spacing of the data points in the surface.

  • When using the Interpolate Vertices Only option, features with vertices that fall outside the data area of the surface will not be part of the output unless the input surface is a raster and the nearest neighbor interpolation method is being used.

Syntax

arcpy.ddd.InterpolateShape(in_surface, in_feature_class, out_feature_class, {sample_distance}, {z_factor}, {method}, {vertices_only}, {pyramid_level_resolution}, {preserve_features})
ParameterExplanationData Type
in_surface

The surface to use for interpolating z-values.

LAS Dataset Layer; Mosaic Layer; Raster Layer; Terrain Layer; TIN Layer
in_feature_class

The input features to process.

Feature Layer
out_feature_class

The feature class that will be produced by this tool.

Feature Class
sample_distance
(Optional)

The spacing at which z-values will be interpolated. By default, this is a raster dataset's cell size or a triangulated surface's natural densification.

Double
z_factor
(Optional)

The factor by which z-values will be multiplied. This is typically used to convert Z linear units to match XY linear units. The default is 1, which leaves elevation values unchanged. This parameter is disabled if the spatial reference of the input surface has a Z datum with a specified linear unit.

Double
method
(Optional)

Interpolation method used to determine elevation values for the output features. The available options depend on the surface type being used.

  • BILINEAR —Determines the value of the query point using bilinear interpolation. This is the default when the input is a raster surface.
  • NEAREST —Determines the value of the query point using nearest neighbor interpolation. When this method is used, surface values will only be interpolated for the input feature's vertices. This option is only available for a raster surface.
  • LINEAR — Default interpolation method for TIN, terrain, and LAS dataset. It obtains elevation from the plane defined by the triangle that contains the XY location of a query point.
  • NATURAL_NEIGHBORS — Obtains elevation by applying area-based weights to the natural neighbors of a query point.
  • CONFLATE_ZMIN — Obtains elevation from the smallest z-value found among the natural neighbors of a query point.
  • CONFLATE_ZMAX — Obtains elevation from the largest z-value found among the natural neighbors of a query point.
  • CONFLATE_NEAREST — Obtains elevation from the nearest value among the natural neighbors of a query point.
  • CONFLATE_CLOSEST_TO_MEAN — Obtains elevation from the z-value that is closest to the average of all the natural neighbors of a query point.
String
vertices_only
(Optional)

Specifies whether the interpolation will only occur along the vertices of an input feature, thereby ignoring the sample distance option.

  • DENSIFY —Interpolates using the sampling distance. This is the default.
  • VERTICES_ONLY —Interpolates along the vertices.
Boolean
pyramid_level_resolution
(Optional)

The z-tolerance or window-size resolution of the terrain pyramid level that will be used by this tool. The default is 0, or full resolution.

Double
preserve_features
(Optional)

Specifies whether features with one or more vertices that fall outside the raster's data area will be retained in the output. This parameter is only available when the input surface is a raster and the nearest neighbor interpolation method is used.

  • PRESERVE —Each vertex that falls outside the raster surface will have its z-value derived from the trend of z-values calculated for the vertices within the raster surface.
  • EXCLUDE —Features with at least one vertex that falls outside the raster surface will be skipped in the output. This is the default.
Boolean

Code sample

InterpolateShape 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.InterpolateShape_3d("my_tin", "roads.shp", "roads_interp.shp")
InterpolateShape example 2 (stand-alone script)

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

'''*********************************************************************
Name: InterpolateShape Example
Description: This script demonstrates how to use InterpolateShape
             on all 2D features in a target workspace.
*********************************************************************'''
# Import system modules
import arcpy
from arcpy import env
import exceptions, sys, traceback

# Set local variables
inWorkspace = arcpy.GetParameterAsText(0)
surface = arcpy.GetParameterAsText(1)

try:
    arcpy.CheckOutExtension("3D")
    # Set default workspace
    env.workspace = inWorkspace
    # Create list of feature classes in target workspace
    fcList = arcpy.ListFeatureClasses()
    if fcList:
        for fc in fcList:
            desc = arcpy.Describe(fc)
            # Find 2D features
            if not desc.hasZ:
                # Set Local Variables
                outFC = "{0}_3D.shp".format(desc.basename)
                method = "BILINEAR"
                # Execute InterpolateShape
                arcpy.ddd.InterpolateShape(surface, fc, outFC, 
                                           10, 1, method, True)
            else:
                print "{0} is not a 2D feature.".format(fc)
    else:
        print "No feature classes were found in {0}.".format(env.workspace)
    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

Licensing information

  • Basic: Requires 3D Analyst
  • Standard: Requires 3D Analyst
  • Advanced: Requires 3D Analyst

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