InterpolateShape(Geometry,SurfaceInterpolationMethod,Double,Double) Method

In This Topic

Interpolates Z values for a geometric shape from the surface layer. This method requires a 3D Analyst license. This method must be called on the MCT. Use QueuedTask.Run.

Syntax

Visual Basic (Declaration)
C#

Public Overloads Function InterpolateShape( _
   ByVal geometry As Geometry, _
   ByVal interpolationMethod As SurfaceInterpolationMethod, _
   ByVal stepSize As Double, _
   ByVal profileWeedTolerance As Double _
) As Geometry

public Geometry InterpolateShape( 
   Geometry geometry,
   SurfaceInterpolationMethod interpolationMethod,
   double stepSize,
   double profileWeedTolerance
)

Parameters

geometry: The geometry to be interpolated. It must be a point, multipoint, polyline or polygon.
interpolationMethod: The method of interpolation. The default method of interpolation for TINs is SurfaceInterpolationMethod.Linear.
stepSize: A densification parameter. If specified, the multipart will be densified by the value prior to interpolating heights from the surface.
profileWeedTolerance: A 2D distance filter to prevent oversampled output. If specified, this value ensures that no two consecutive vertices will be closer than this distance. Use 0 to turn off weeding.

Return Value

A ArcGIS.Core.Geometry.Geometry with surface elevation z values.

Exceptions

Exception	Description
System.ArgumentNullException	geometry cannot be null.
System.ArgumentException	The set of parameters is invalid for this surface. See CanInterpolateShape.
MappingException	An exception occurred within the InterpolateShape calculation.
ArcGIS.Core.CalledOnWrongThreadException	This method or property must be called within the lambda passed to QueuedTask.Run.
ArcGIS.Core.Licensing.Exceptions.LicenseException	A 3D Analyst license is required.

Remarks

Portions of the input not falling within the interpolation zone of the surface will be clipped.

Input polylines and polygons are densified by the stepSize. This takes place before interpolating heights from the surface. The densification ensures no two vertices are spaced more than stepSize apart.

If the interpolation method is linear and the surface is a TIN, the stepSize argument isn't very important since the default sampling scheme of using input vertices and triangle edge intersections is sufficient to capture all surface information. The use of stepSize is more relevant when the interpolation method is something other than linear.

If the interpolation method is natural neighbors, a stepSize less than or equal to 0 outputs input vertices and hard edge crossings only. If stepSize is NaN, the output includes the input vertices and all triangle edge intersections.

Weeding is most applicable when using linear interpolation. This is because the 'natural densification' used by linear interpolation, the insertion of vertices at triangle edge intersections, can result in very closely spaced vertices at certain locations. To turn off weeding set the profileWeedTolerance to 0.

InterpolateShape will handle differences in spatial reference between the input shape and the surface. It will project (a copy of) the input geometry to match the surface for the sake of interpolation. It will then re-project the output geometry so it's the same as the input shape.

Example

Interpolate Shape

{
  // Note: Needs QueuedTask to run
  // Note: Needs 3d Analyst license to run
  {
    ArcGIS.Core.Geometry.Geometry output = null;
    // interpolate z values for a geometry
    if (tinLayer.CanInterpolateShape(polyline))
      output = tinLayer.InterpolateShape(polyline, SurfaceInterpolationMethod.NaturalNeighbor);

    if (output != null)
    {
      // process the output
    }

    // densify the shape before interpolating
    if (tinLayer.CanInterpolateShape(polygon))
      output = tinLayer.InterpolateShape(polygon, SurfaceInterpolationMethod.Linear, 0.01, 0);

    if (output != null)
    {
      // process the output
    }
  }
}

Requirements

Target Platforms: Windows 11 Home, Pro, Enterprise (64 bit)

ArcGIS Pro version: 3.4 or higher.

Reference

TinLayer Class
TinLayer Members
Overload List

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