Interpolate Shape (3D Analyst)

Summary

Interpolates z-values for a feature class based on elevation derived from a raster, triangulated irregular network (TIN), or terrain dataset.

Learn more about how Interpolate Shape (3D Analyst) works

Illustration

Usage

• When using the natural neighbors interpolation option, make sure to specify a reasonable sample distance. This usually falls between 0.5 and 1.0 times the average point spacing of the data used to build the TIN or terrain dataset.

• When using the Interpolate Vertices Only option, input features with vertices that fall outside the data area of the surface will be ignored and not output. Clip features prior to running Interpolate Shape to ensure the features are completely on the surface.

• The Z factor parameter only affects results for rasters and TINs, not terrain datasets. To apply a z factor to features made from a terrain dataset use the Adjust 3D Z tool.

Syntax

InterpolateShape_3d (in_surface, in_feature_class, out_feature_class, {sample_distance}, {z_factor}, {method}, {vertices_only}, {pyramid_level_resolution})

Parameter	Explanation	Data Type
in_surface	The raster, TIN, or terrain surface used for interpolating z-values.	Raster Layer; Terrain Layer; TIN Layer
in_feature_class	The input feature class.	Feature Layer
out_feature_class	The output feature class.	Feature Class
sample_distance (Optional)	The spacing at which z-values will be interpolated. By default, this is a raster's cell size or a TIN's natural densification.	Double
z_factor (Optional)	The factor by which elevation values will be multiplied. This is typically used to convert Z linear units that match those of the XY linear units. The default is 1, which leaves elevation values unchanged.	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 interpolation is available for a raster surface, where a query point obtains its elevation from the values found in the four nearest cells. Terrain and TIN datasets provide the following options: LINEAR — Default interpolation method. 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

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

Current Workspace, Scratch Workspace, Extent, Output Coordinate System, Geographic Transformations, XY Resolution, XY Tolerance, Z Resolution, Z Tolerance, Output CONFIG Keyword, Output Spatial Grid 1, 2, 3, Auto Commit

Licensing Information

ArcView: Requires 3D Analyst

ArcEditor: Requires 3D Analyst

ArcInfo: Requires 3D Analyst