public class ExampleClass : MonoBehaviour {
    public float speed = 5;

    // 跟随摄像机的移动要写在LateUpdate中
    void LateUpdate() {
        transform.Translate(0, 0, Time.deltaTime * speed);
    }
}

public class ExampleClass : MonoBehaviour {
    public float speed = 6.0f;
    Vector3 movement;
    void Start()
    {
        playerRigidbody = rigidbody;
    }
    void FixedUpdate()
    {
        // 角色控制
        float h = Input.GetAxisRaw("Horizontal"); // 获取横轴值
        float v = Input.GetAxisRaw("Vertical");   // 获取纵轴值
        Move(h, v);
    }
    void Move(float h, float v)
    {
        movement.Set(h, 0, v);
        movement = movement.normalized * speed * Time.deltaTime;
        playerRigidbody.MovePosition(transform.position + movement);
    }
}

public class ExampleClass : MonoBehaviour {
    // 获取摇杆值
    float moveHorizontal = Input.GetAxis("Horizontal");
    float moveVertical = Input.GetAxis("Vertical");

    // 改变速度
    rigidbody.velocity = new Vector3(moveHorizontal, 0.0f, moveVertical) * speed;
}