NearestPoint3D Method (IGeometryEngine)

In This Topic

Finds the nearest point, in 3D space, on a Z-Aware geometry to a specified point.

Syntax

C#
Visual Basic (Declaration)

ProximityResult NearestPoint3D( 
   Geometry geometry,
   MapPoint point
)

Function NearestPoint3D( _
   ByVal geometry As Geometry, _
   ByVal point As MapPoint _
) As ProximityResult

Parameters

geometry: The geometry.
point: The point to which the returned point will be nearest.

Return Value

ProximityResult.

If the input geometry is a non-empty point, then ProximityResult.PointIndex = 0, ProximityResult.PartIndex = 0, and ProximityResult.SegmentIndex is null.

If the input geometry is a non-empty multipoint, ProximityResult.PointIndex is the index of the nearest point in the Multipoint, ProximityResult.PartIndex = ProximityResult.PointIndex, and ProximityResult.SegmentIndex is null.

Otherwise, if the input geometry is non-empty, then ProximityResult.PointIndex is null and ProximityResult.SegmentIndex is the segment which contains the nearest point. The segment index is relative to the ProximityResult.PartIndex. For example, if the segment index = 0 and the part index = 2, then the segment containing the nearest point is segment 0 of part 2. In other words, the segment is the first segment of the third part.

Proximity.RightSide is irrelevant for 3D operations and is always set to false.

If either of the input geometries are empty, then ProximityResult.Distance = -1, ProximityResult.Point is empty, ProximityResult.PartIndex = -1, ProximityResult.PointIndex is null, and ProximityResult.SegmentIndex null.

Exceptions

Exception	Description
System.ArgumentNullException	Either geometry or point or both are null.
System.NotImplementedException	The method is not implemented for GeometryBag.
System.InvalidOperationException	The geometry is not Z-Aware.
System.NotImplementedException	This function is not implemented for envelopes.
ArcGIS.Core.Geometry.Exceptions.OperationException	Cannot do 3D operations on curve segments.

Remarks

The nearest point does not have to be a vertex of the input geometry. It can be any point contained in the geometry.

GeometryEngine NearestPoint3D

Example

Determine Nearest Point in 3D

MapPoint pt1 = MapPointBuilderEx.CreateMapPoint(1, 1, 1);
MapPoint pt2 = MapPointBuilderEx.CreateMapPoint(2, 2, 2);
MapPoint pt3 = MapPointBuilderEx.CreateMapPoint(10, 2, 1);

//
// test pt1 to pt2
//
ProximityResult result = GeometryEngine.Instance.NearestPoint3D(pt1, pt2);
// result.Point = 1,1,1
// result.Distance = Math.Sqrt(3)
// result.SegmentIndex = null
// result.PartIndex = 0
// result.PointIndex = 0
// result.RightSide = false

// 
// multipoint built from pt1, pt2.   should be closer to pt2
// 
Multipoint multipoint = MultipointBuilderEx.CreateMultipoint(new List<MapPoint>() { pt1, pt2 });
result = GeometryEngine.Instance.NearestPoint3D(multipoint, pt3);
// result.Point = 2, 2, 2
// result.Distance = Math.Sqrt(65)
// result.SegmentIndex = null
// result.PartIndex = 1
// result.PointIndex = 1
// result.RightSide = false

Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.

Reference

IGeometryEngine Interface
IGeometryEngine Members

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