如何通过触摸输入旋转对象并在 Unity 中缓慢停止？

Question

我从这里得到了一些代码： https://answers.unity.com/questions/34317/rotate-object-with-mouse-cursor-that-slows-down-on.html

 private float rotationSpeed = 10.0F;
 private float lerpSpeed = 1.0F;

 private Vector3 theSpeed;
 private Vector3 avgSpeed;
 private bool isDragging = false;
 private Vector3 targetSpeedX;

 void OnMouseDown() {

     isDragging = true;
 }

 void Update() {

     if (Input.GetMouseButton(0) && isDragging) {
         theSpeed = new Vector3(-Input.GetAxis("Mouse X"), Input.GetAxis("Mouse Y"), 0.0F);
         avgSpeed = Vector3.Lerp(avgSpeed, theSpeed, Time.deltaTime * 5);
     } else {
         if (isDragging) {
             theSpeed = avgSpeed;
             isDragging = false;
         }
         float i = Time.deltaTime * lerpSpeed;
         theSpeed = Vector3.Lerp(theSpeed, Vector3.zero, i);
     }

     transform.Rotate(Camera.main.transform.up * theSpeed.x * rotationSpeed, Space.World);
     transform.Rotate(Camera.main.transform.right * theSpeed.y * rotationSpeed, Space.World);
 }

此代码通过鼠标单击和拖动来旋转对象，单击后，对象会缓慢停止。我现在想要这个功能在手机上。这是我的移动版代码：

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

    // Track a single touch as a direction control.
    if (Input.touchCount > 0) {
        Touch touch = Input.GetTouch(0);

        // Handle finger movements based on touch phase.
        switch (touch.phase) {
            // Record initial touch position.
            case TouchPhase.Began:
                startPos = touch.position;
                directionChosen = false;
                break;

            // Determine direction by comparing the current touch position with the initial one.
            case TouchPhase.Moved:
                direction = touch.position - startPos;
                break;

            // Report that a direction has been chosen when the finger is lifted.
            case TouchPhase.Ended:
                directionChosen = true;
                stopSlowly = true;
                Debug.Log("end");
                break;
        }
    }
    if (directionChosen) {
        // Something that uses the chosen direction...
        theSpeed = new Vector3(-direction.x, direction.y, 0.0F);
        avgSpeed = Vector3.Lerp(avgSpeed, theSpeed, Time.deltaTime * 5);
    } else {
        if (stopSlowly) {
            Debug.Log("TESTOUTPUT");
            theSpeed = avgSpeed;
            isDragging = false;
        }
        float i = Time.deltaTime * lerpSpeed;
        theSpeed = Vector3.Lerp(theSpeed, Vector3.zero, i);
    }

    transform.Rotate(camera.transform.up * theSpeed.x * rotationSpeed, Space.World);
    transform.Rotate(camera.transform.right * theSpeed.y * rotationSpeed, Space.World);

这里有一些变量，我使用 Vector2 变量作为 startPos 和方向：

private float rotationSpeed = 1f;
private float lerpSpeed = 1.0F;

private Vector3 theSpeed;
private Vector3 avgSpeed;
private bool isDragging = false;
private Vector3 targetSpeedX;


public Vector2 startPos;
public Vector2 direction;
public bool directionChosen;
public bool stopSlowly;

现在，如果我按下播放键并旋转手机上的对象，它会旋转，但不会自行结束。它的旋转速度也非常快。当我一次触摸对象时，它立即停止。 请有人能告诉我我的代码到底有什么问题。我的目标只是旋转，从触摸输入初始化，然后缓慢结束直到静止。

谢谢

Answer 1

我现在使用一些物理学来解决这个问题：

// React on User Touch Input -> Rotate gameObject
        if (Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Moved) {
            // Get movement of the finger since last frame
            Vector2 touchDeltaPosition = Input.GetTouch(0).deltaPosition;

            // Add Torque to gameObject
            rb.AddTorque(camera.transform.up * -touchDeltaPosition.x/* * optionalForce*/);
            rb.AddTorque(camera.transform.right * touchDeltaPosition.y/* * optionalForce*/);
        } else if (Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Ended) {
            // throw anker, stop rotating slowly
            rb.angularDrag = 0.7f;
        }

此代码用于触摸输入并旋转对象 + 将其缓慢停止。您需要在要旋转的对象上使用刚体。这里称为rb。相机是我的主相机。

Answer 2

你的情况很混乱。 试试这样的

    // Handle finger movements based on touch phase.
    switch (touch.phase) {
        // Record initial touch position.
        case TouchPhase.Began:
            startPos = touch.position;
            break;

        // Determine direction by comparing the current touch position with the initial one.
        case TouchPhase.Moved:
            direction = touch.position - startPos;
            isDragging = true;
            break;

        // Report that a direction has been chosen when the finger is lifted.
        case TouchPhase.Ended:
            isDragging = false;
            stopSlowly = true;
            Debug.Log("end");
            break;
    }

if (isDragging) {
    // Something that uses the chosen direction...
    theSpeed = new Vector3(-direction.x, direction.y, 0.0F);
    avgSpeed = Vector3.Lerp(avgSpeed, theSpeed, Time.deltaTime * 5);
} else {
    if(stopSlowly) {
        Debug.Log("TESTOUTPUT");
        theSpeed = avgSpeed;
        stopSlowly = false;
    }
    float i = Time.deltaTime * lerpSpeed;
    theSpeed = Vector3.Lerp(theSpeed, Vector3.zero, i);
}