ArcGIS Pro 3.3 API Reference Guide
ArcGIS.Core.Geometry Namespace / IGeometryEngine Interface / NearestPoint3D Method
The geometry.
The point to which the returned point will be nearest.
Example

In This Topic
    NearestPoint3D Method (IGeometryEngine)
    In This Topic
    Finds the nearest point, in 3D space, on a Z-Aware geometry to a specified point.
    Syntax
    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
    ExceptionDescription
    Either geometry or point or both are null.
    The method is not implemented for GeometryBag.
    The geometry is not Z-Aware.
    This function is not implemented for envelopes.
    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.
    See Also