在 Unity 中拖动相机时如何防止鬼影移动？

Question

I have the below script attached to my main camera. Its for a VR app. The script allows me to rotate the camera when pressing down on the mouse button.

The script works but the problem is, while I have the mouse button pressed down the view slightly keeps rotating towards the left. When I release the mouse button the movement stops.

I cant find the cause of this "ghost" movement

public class DragCamera : MonoBehaviour
{
    // flag to keep track whether we are dragging or not
    bool isDragging = false;

    // starting point of a camera movement
    float startMouseX;
    float startMouseY;

    // Camera component
    Camera cam;

    // Use this for initialization
    void Start()
    {
        // Get our camera component
        cam = GetComponent<Camera>();
        Cursor.visible = false;
    }

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

        // if we press the left button and we haven't started dragging
        if (Input.GetMouseButtonDown(0) && !isDragging)
        {
            // set the flag to true
            isDragging = true;

            // save the mouse starting position
            startMouseX = Input.mousePosition.x;
            startMouseY = Input.mousePosition.y;
        }
        // if we are not pressing the left btn, and we were dragging
        else if (Input.GetMouseButtonUp(0) && isDragging)
        {
            // set the flag to false
            isDragging = false;
        }
    }

    void LateUpdate()
    {
        // Check if we are dragging
        if (isDragging)
        {
            //Calculate current mouse position
            float endMouseX = Input.mousePosition.x;
            float endMouseY = Input.mousePosition.y;

            //Difference (in screen coordinates)
            float diffX = endMouseX - startMouseX;
            float diffY = endMouseY - startMouseY;

            //New center of the screen
            float newCenterX = Screen.width / 2 + diffX;
            float newCenterY = Screen.height / 2 + diffY;

            //Get the world coordinate , this is where we want to look at
            Vector3 LookHerePoint = cam.ScreenToWorldPoint(new Vector3(newCenterX, newCenterY, cam.nearClipPlane));

            //Make our camera look at the "LookHerePoint"
            transform.LookAt(LookHerePoint);

            //starting position for the next call
            startMouseX = endMouseX;
            startMouseY = endMouseY;
        }
    }
}

Answer 1

 float newCenterX = Screen.width / 2 + diffX; float newCenterY = Screen.height / 2 + diffY;

You may want to consider using parenthesis around math involving multiplication/division, and addition/subtracting. This helps prevent the compiler from interpreting float newCenterX = Screen.width / 2 + diffX; as

float newCenterX = Screen.width / (2 + diffX);

instead of the intended

float newCenterX = (Screen.width / 2) + diffX;

When using the mono compiler (unity) I've personally found that it takes division by integers literally. ie. 12f / 2 and rounds it to the nearest integer some times. Try to explicitly divide by the same primitive type such as 12f / 2f