API Reference › core-geometry› Curve › Arc3d › ClosestPointXY

closestPointXY Method

Search for a point on the Arc3d that is closest to the spacePoint as viewed in the xy-plane (ignoring z).

  • If the space point is exactly on the curve, this is the reverse of fractionToPoint.
  • Since CurvePrimitive should always have start and end available as candidate points, this method should always succeed.

closestPointXY(spacePoint: Point3d, extend: VariantCurveExtendParameter = false, result?: CurveLocationDetail): undefined | CurveLocationDetail

@returns details of the closest point.

Parameter Type Description
spacePoint Point3d point in space.
extend VariantCurveExtendParameter if true, consider projections to the complete ellipse. If false (default), consider only endpoints
and projections within the arc sweep. Note that for an open arc, extending one end is the same as extending both ends.
result CurveLocationDetail (optional) pre-allocated detail to populate and return.

Returns - undefined | CurveLocationDetail

details of the closest point.

Defined in

Last Updated: 06 March, 2026