更普遍的做法是将一个预设(Prefab)拖到脚本的相应公有成员变量上，实例化的时候直接对这个成员变量进行实例化就可以。

// Instantiate a rigidbody then set the velocity
var projectile : Rigidbody;
function Update () {
	// Ctrl was pressed, launch a projectile
	//按Ctrl发射炮弹
	if (Input.GetButtonDown("Fire1")) {
		// Instantiate the projectile at the position and rotation of this transform
		//在该变换位置和旋转。实例化炮弹
		var clone : Rigidbody;
		clone = Instantiate(projectile, transform.position, transform.rotation);

		// Give the cloned object an initial velocity along the current object's Z axis
		//沿着当前物体的Z轴给克隆的物体一个初速度。

		clone.velocity = transform.TransformDirection (Vector3.forward * 10);
	}
}

   同一时候也有一个Destroy函数在帧更新函数完毕后或设定的一个延时时间后销毁一个对象。

// Kills the game object
//销毁游戏物体
Destroy (gameObject);

// Removes this script instance from the game object
//从游戏物体删除该脚本实例
Destroy (this);

// Removes the rigidbody from the game object
//从游戏物体删除刚体
Destroy (rigidbody);

// Kills the game object in 5 seconds after loading the object
//载入物体5秒后销毁游戏物体
Destroy (gameObject, 5);

// When the user presses Ctrl, it will remove the script
// named FooScript from the game object
//当按下Ctrl将从游戏物体删除名为FooScript的脚本
function Update () {
	if (Input.GetButton ("Fire1") && GetComponent (FooScript))
		Destroy (GetComponent (FooScript));
}

    注意到Destroy函数能够销毁单独的组件而不正确游戏对象本身产生影响，一个通常易犯的错误是Destroy(this); 这句代码只销毁脚本组件，而不销毁该脚本所附加在的对象。

4. 协程(Coroutines)

IEnumerator Fade() {  
   for (float f = 1f; f <= 0; f -= 0.1f) {  
      Color c = renderer.material.color;  
      c.alpha = f;  
      renderer.material.color = c;  
      yield return;  
   }  
}  

void Update() {  
   if (Input.GetKeyDown("f")) {  
      StartCoroutine("Fade");  
   }  
} 

IEnumerator Fade() {  
	for (float f = 1f; f <= 0; f -= 0.1f) {  
		Color c = renderer.material.color;  
		c.alpha = f;  
		renderer.material.color = c;  
		yield return new WaitForSeconds(.1f);  
	}  
}