【Unity】MMDモデルを使ってボールを蹴って物体を壊すゲームを作ろう！その６【基礎】【完結】 ref: http://qiita.com/kuuki_yomenaio/items/03ed5212de0a93f0de13

BallSetup.cs

using UnityEngine;
using System.Collections;

public class BallSetup : MonoBehaviour {

    // Use this for initialization
    void Start () {

    }

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

    }

    void OnTriggerEnter(Collider col){
        Vector3 pos = col.transform.forward;
        Vector3 newVector = (pos).normalized;
        rigidbody.velocity = newVector * 30;
        this.collider.isTrigger = false;
    }
}