Get the point on a polyline (in 3D space) which is closest to the current mouse position.
public static Vector3 ClosestPointToArc(Vector3 center, Vector3 normal, Vector3 from, float angle, float radius) { Vector3[] array = new Vector3[60]; Handles.SetDiscSectionPoints(array, center, normal, from, angle, radius); return HandleUtility.ClosestPointToPolyLine(array); }