ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.Geometry Namespace / IGeometryEngine Interface / NearestPoint Method
The geometry.
The point to which the returned point will be nearest.
Example Version

NearestPoint Method (IGeometryEngine)
Finds the nearest point in the geometry to a specified point.
Syntax

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.

ProximityResult.RightSide specifies if the input query point is on the right side of the input geometry or not.

If either of the input geometries are empty, then ProximityResult.Distance = -1, ProximityResult.Point is empty, ProximityResult.RightSide = false, 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.
This function is not implemented for envelopes.
Remarks
The nearest point does not have to be a vertex of the input geometry. It can be any point on the geometry. If the geometry is a Polygon, then the nearest point will be a point on the boundary of the Polygon.

GeometryEngine NearestPoint

Example
Nearest Point versus Nearest Vertex
SpatialReference sr = SpatialReferences.WGS84;
MapPoint pt = MapPointBuilderEx.CreateMapPoint(5, 5, sr);

List<Coordinate2D> coords = new List<Coordinate2D>()
{
  new Coordinate2D(10, 1),
  new Coordinate2D(10, -4),
  new Coordinate2D(0, -4),
  new Coordinate2D(0, 1),
  new Coordinate2D(10, 1)
};

Polygon polygon = PolygonBuilderEx.CreatePolygon(coords);

// find the nearest point in the polygon geomtry to the pt
ProximityResult result = GeometryEngine.Instance.NearestPoint(polygon, pt);
// result.Point = 5, 1
// result.SegmentIndex = 3
// result.PartIndex = 0
// result.PointIndex = null
//result.Distance = 4
//result.RightSide = false

// find the nearest vertex in the polgyon geometry to the pt
result = GeometryEngine.Instance.NearestVertex(polygon, pt);
// result.Point = 10, 1
// result.PointIndex = 0
// result.SegmentIndex = null
// result.PartIndex = 0
// result.Distance = Math.Sqrt(41)
// result.RightSide = false
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also