对象跟随鼠标拖动 Unity 3D

Question

我有一个对象不断向前移动，我想通过鼠标拖动屏幕的任何部分（滑动）使它在 X 轴上移动，所以我尝试了这段代码，但是当第一次点击屏幕时，对象移动到鼠标 X 位置（不拖动）！你对如何让它只在拖动时移动有什么建议吗？

脚本：

private bool dragging = false;
private float distance;

public Rigidbody Ball;
public float Speed = 100;


// Use this for initialization
void Start () {

}

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

    Ball.velocity = transform.forward * Speed * Time.deltaTime;
}


void Update()
{
    if (Input.GetMouseButtonDown(0))
    {
        distance = Vector3.Distance(transform.position, Camera.main.transform.position);
        dragging = true;
    }

    if(Input.GetMouseButtonUp(0))
    {
        dragging = false;
    }

    if (dragging)
    {
        Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
        Vector3 rayPoint = ray.GetPoint(distance);
        transform.position = new Vector3(rayPoint.x, transform.position.y, transform.position.z);
    }
}

Answer 1

对于继续移动，您可以使用GetMouseButton，在按钮保持按下状态时为真（与GetMouseButtonDown 相反，仅在按下按钮的第一帧时为真）

您说脚本与RigiBody 组件相同。在这种情况下，您永远不应该使用

transform.position = ...

但改用RigidBody.MovePosition like

Ball.MovePosition(new Vector3( ... ));

最后存储鼠标按下时的初始位置，然后将其用作参考点：

Vector3 initialPosition;

void Update()
{
    // called the first time mouse button is pressed
    if (Input.GetMouseButtonDown(0))
    {
        Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
        initialPosition = transform.position;

        Vector3 rayPoint = ray.GetPoint(0);

        // Not sure but this might get you a slightly better value for distance
        distance = Vector3.Distance(transform.position, rayPoint );
    }

    // called while button stays pressed
    if (Input.GetMouseButton(0))
    {
        Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
        Vector3 rayPoint = ray.GetPoint(distance);
        Ball.MovePosition(initialPosition + new Vector3(rayPoint.x, 0, 0));
    }
}

---

另外请注意，我不确定

// Update is called once per frame
void FixedUpdate () {
    Ball.velocity = transform.forward * Speed * Time.deltaTime;
}

是你想要做的。在我看来，Time.deltaTime 的使用在这里没有多大意义。您要么想将速度设置为某个速度，例如

Ball.velocity = transform.forward * Speed;

或者您想使用Time.deltaTime 更改位置以实现平滑移动

Ball.MovePosition(transform.position + transform.forward * Speed * Time.deltaTime);