貪喫蛇小遊戲2d

（一）場景設置
1.攝像機正交
2.創建一個Quad（create ->3D）當背景，上面放上方塊，這樣全都能顯示出來，不能用畫布，顯示不出來
3.材質球，物體有陰影，把材質球的shader改成Unlit/color
4.分辨率，設置成16:9
5.調整攝像機的視角，（23)

（二）頭部移動
掛一個Move腳本

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
public class Move : MonoBehaviour {
    public GameObject head;
    Vector2 direction  = Vector2.up;//不指明一開始的方向，運行頭部不移動
    public GameObject food;
    // Use this for initialization
    void Start () {
        InvokeRepeating ("MoveSnack",0.5f,0.5f);

    }

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

        if(Input.GetKey(KeyCode.W)){
            direction = Vector2.up; 

        }
        if(Input.GetKey(KeyCode.S)){
            direction = Vector2.down;

        }
        if(Input.GetKey(KeyCode.A)){
            direction = Vector2.left;
        }
        if(Input.GetKey(KeyCode.D)){
            direction = Vector2.right;
        }

    }

    void MoveSnack(){
        transform.Translate (direction);//transform前沒有東西
    }

（三）食物生成

using UnityEngine;
using System.Collections;

public class Food : MonoBehaviour {
    public GameObject foodss;
    public int xx=30;
    public int yy=20;
    // Use this for initialization
    void Start () {
        InvokeRepeating ("CreateFood",0.5f,5);
    }

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

    }

    void    CreateFood(){
       int x = Random.Range (-xx,xx);
        int y = Random.Range (-yy,yy);
        Instantiate (foodss,new Vector2(x,y),Quaternion.identity);
    }
}

（四）
食物碰撞後消失

void OnTriggerEnter(Collider other){
        if(other.gameObject.CompareTag("food")){
            Destroy(other.gameObject);
        }}

放在Move腳本上
同時head頭部上要掛上剛體Rigidoby，不使用重力，盒子碰撞體，並且勾選trigger，
food上掛盒子碰撞體，不勾選trigger，這樣頭部碰撞到食物就會消失，爲了防止頭部擦過食物，食物消失，所以把食物的盒子碰撞器的scale由原來的1變成0.5
（五）生成下一段身體，並且隨着頭部移動（核心）

也寫在Move腳本上

public GameObject body;
    public float time = 0.8f;
    public bool Switch;//true的時候實例化出來身體
    List<Transform> bodyv = new List<Transform>();
    void MoveSnack(){
        Vector3 VPosition = transform.position;//頭的位置，
        transform.Translate (direction);
        if(Switch){
            GameObject Bodya = (GameObject)Instantiate (body,VPosition,Quaternion.identity);//在頭的位置那生成身體
            bodyv.Insert(0,Bodya.transform);
            Switch = false;
        }
        else if(bodyv.Count >0){
            bodyv.Last ().position = VPosition;
            bodyv.Insert (0,bodyv.Last());
            bodyv.RemoveAt (bodyv.Count-1);
        }
    }
    void OnTriggerEnter(Collider other){
        if(other.gameObject.CompareTag("food")){
            Switch = true;
            Destroy(other.gameObject);
        }}

（六）死亡判定

void OnTriggerEnter(Collider other){
        if (other.gameObject.CompareTag ("food")) {
            Switch = true;
            Destroy (other.gameObject);
        } else {

            SceneManager.LoadScene (0);//重新加載
        }
    }