如何正確使用鼠標在一個軸上旋轉 2D 對象

Question

目標是在按住鼠標按鈕的同時旋轉磁盤。

以下代碼完美地完成了它的工作 - 正是我想要的：

public class Rotator : MonoBehaviour {

    private void OnMouseDrag()
    {

        Vector3 difference = Camera.main.ScreenToWorldPoint(Input.mousePosition) - transform.position;
        difference.Normalize();
        float rotation_z = Mathf.Atan2(difference.y, difference.x) * Mathf.Rad2Deg;
        transform.rotation = Quaternion.Euler(0f, 0f, rotation_z);
        
    }

}

除了在不拖動的情況下正常單擊時出現的異常磁盤行為：

我怎樣才能防止這種旋轉跳躍？ 我只需要拖動時平滑旋轉。

Answer 1

由於您只想在拖動時應用此功能，因此我會這樣做

• OnMouseDown -> 存儲初始鼠標偏移和當前旋轉
• OnMouseDrag -> 使用原始和當前鼠標偏移之間的增量來計算從初始旋轉 + 增量的旋轉

就像是

private Vector2 startDelta;
private Quaternion startRotation;

private void OnMouseDown()
{
    // Store the initial mouse offset
    startDelta = (Camera.main.ScreenToWorldPoint(Input.mousePosition) - transform.position);
    startDelta.Normalize();

    // Store the initial rotation
    startRotation = transform.rotation;
}

private void OnMouseDrag()
{
    // Get the current mouse offset
    Vector2 currentDelta = (Camera.main.ScreenToWorldPoint(Input.mousePosition) - transform.position);
    currentDelta.Normalize();

    // Get the angle difference between the initial and current offset
    var rotation_z = Vector2.SignedAngle(startDelta, currentDelta);

    // From the initial rotation rotate about the calculated difference angle
    transform.rotation = startRotation * Quaternion.Euler(0f, 0f, rotation_z);
}