Vector3

• Vector3.up：即 Vector3(0, 1, 0)
• Vector3.down：即 Vector3(0, -1, 0)
• Vector3.forward：即 Vector3(0, 0, 1)
• Vector3.back：即 Vector3(0, 0, -1)
• Vector3.right：即 Vector3(1,0, 0)
• Vector3.left：即 Vector3(-1, 0, 0)

在 Scene 中画线（脚本挂给Cube）

    void FixedUpdate()
    {
        Debug.DrawRay(transform.position, Vector3.up * 10, Color.black);//黑色
 
        Debug.DrawRay(transform.position, Vector3.down * 10, Color.blue);//蓝色
 
        Debug.DrawRay(transform.position, Vector3.forward * 10, Color.cyan);//青色
 
        Debug.DrawRay(transform.position, Vector3.back * 10, Color.yellow);//黄色
 
        Debug.DrawRay(transform.position, Vector3.left * 10, Color.magenta);//洋红
 
        Debug.DrawRay(transform.position, Vector3.right * 10, Color.green);//绿色
    }

 结果

 Transform

• transform.up：即 Vector3.up
• transform.forward：即 Vector3.forward
• transform.right：即 Vector3.right

tranform 是基于自身坐标系，而 Vector3 是基于世界坐标系。

    void FixedUpdate()
    {
        Debug.DrawRay(transform.position, transform.up * 10, Color.yellow); //黄色
        Debug.DrawRay(transform.position, transform.forward * 10, Color.cyan); //青色
        Debug.DrawRay(transform.position, transform.right * 10, Color.green); //绿色
        
        Debug.DrawRay(transform.position, Vector3.up * 10, Color.magenta); 
        Debug.DrawRay(transform.position, Vector3.down * 10, Color.magenta); 
        Debug.DrawRay(transform.position, Vector3.forward * 10, Color.magenta); 
        Debug.DrawRay(transform.position, Vector3.back * 10, Color.magenta); 
        Debug.DrawRay(transform.position, Vector3.left * 10, Color.magenta); 
        Debug.DrawRay(transform.position, Vector3.right * 10, Color.magenta); 
    }

效果