Getting ready

We need to define a custom data type called PathSegment:

using UnityEngine; 
using System.Collections; 
 
public class PathSegment 
{ 
    public Vector3 a; 
    public Vector3 b; 
 
    public PathSegment () : this (Vector3.zero, Vector3.zero){} 
    public PathSegment (Vector3 a, Vector3 b) 
    { 
        this.a = a; 
        this.b = b; 
    } 
}