API Reference › core-geometry› CartesianGeometry › PolygonOps › ClosestPoint

closestPoint MethodStatic

Compute the closest point on the polygon boundary or its interior to the given point.

closestPoint(polygon: IndexedXYZCollection | Point3d[], testPoint: Point3d, tolerance: number = Geometry.smallMetricDistance, result?: PolygonLocationDetail): PolygonLocationDetail

@returns details d of the closest point d.point:

  • d.isValid() returns true if and only if the polygon is nontrivial.
  • d.edgeIndex and d.edgeParam specify the location of the (nearest) boundary point.
  • d.code classifies the closest point: PolygonLocation.OnPolygonVertex, PolygonLocation.OnPolygonEdgeInterior, PolygonLocation.InsidePolygonProjectsToVertex, or PolygonLocation.InsidePolygonProjectsToEdgeInterior.
  • d.a is the distance from testPoint to the closest point.
Parameter Type Description
polygon IndexedXYZCollection | Point3d[] points of the polygon, closure point optional
testPoint Point3d point p to project onto the polygon edges. Works best when p is in the plane of the polygon.
tolerance number optional distance tolerance for distinguishing boundary versus interior closest point.
result PolygonLocationDetail optional pre-allocated object to fill and return

Returns - PolygonLocationDetail

details d of the closest point d.point:

  • d.isValid() returns true if and only if the polygon is nontrivial.
  • d.edgeIndex and d.edgeParam specify the location of the (nearest) boundary point.
  • d.code classifies the closest point: PolygonLocation.OnPolygonVertex, PolygonLocation.OnPolygonEdgeInterior, PolygonLocation.InsidePolygonProjectsToVertex, or PolygonLocation.InsidePolygonProjectsToEdgeInterior.
  • d.a is the distance from testPoint to the closest point.

Defined in

Last Updated: 29 October, 2025