Fixed simple rope interpolation

using UnityEngine;
using System.Collections;

public class Rope : MonoBehaviour
{

    public int numJoints = 7;
    public Transform source;
    public Transform dest;

    Transform[] bones;

    // Use this for initialization
    void Start ()
    {

        bones = new Transform[numJoints];

        bones[0] = source;
        bones[numJoints - 1] = dest;

        for (int n = 1; n < numJoints - 1; ++n) {
            bones[n] = GameObject.CreatePrimitive (PrimitiveType.Sphere).transform;
        }

    }

    // Update is called once per frame
    void Update ()
    {

        float length = (dest.position - source.position).magnitude;

        for (int n = 1; n < numJoints - 1; ++n) {

            float i = Mathf.InverseLerp (0, bones.Length - 1, n);
            float si = Mathf.SmoothStep (0, 1, i);

            Vector3 sourceLine = source.position + source.forward * length * i;
            Vector3 destLine = dest.position - dest.forward * length * (1 - i);

            Vector3 pos = Vector3.Lerp (sourceLine, destLine, si);
            Quaternion rot = Quaternion.Slerp (source.rotation, dest.rotation, si);

            bones[n].position = pos;
            bones[n].rotation = rot;
        }

    }

}