So, Hey guys. Im new to Unity and Im trying a very simple code that allows the player to Zoom-in & Zoom-Out. Here's the code of it:

[Header("Vertical Zooming")]
[SerializeField] private float zoomSpeed;

private void Update()
{
    VerticalZooming();
}

private void VerticalZooming()
{
    Vector3 initialPosition = new Vector3();
    // bool canMove = false;

    if (Input.GetMouseButtonDown(0))
    {
        initialPosition = mCamRef.ScreenToViewportPoint(Input.mousePosition);
        Debug.Log(initialPosition.y);
       
    }

    if (Input.GetMouseButton(0))
    {
        Vector3 newPosition = mCamRef.ScreenToViewportPoint(Input.mousePosition);
        Debug.Log("newPosition"   newPosition.y);

        if (newPosition.y < initialPosition.y)
        {    
            Zoom((zoomSpeed * Time.deltaTime) * -1f);
        }
        if (newPosition.y > initialPosition.y)
        {
            Zoom(zoomSpeed * Time.deltaTime);
        }

       intialPosition = newPosition;
    }
}

private void Zoom(float inZoomSpeed)
{
    transform.Translate(mCamRef.transform.position.z * inZoomSpeed * transform.forward);
}

So, if you see the code above. On mousebuttondown we note down the initial position and on holding the mouse button we keep track of new position constantly.. What i want is pretty simple. With reference to my initial mouse click im checking if my new position is greater in y is yes i need to zoom out. If new position is lower than initial position in y-axis. Them, i need to zoom in. Which I did, But for some reason its not working. Two problems here:

1. Though if there is no change to newposition i.e., even if both my newposition variable and initial position variable are in same spot my camera moves(Zoom-out in my case) which shouldn't happen. It should only happen if my newPosition.y variable is greater that that of initialposition.y. I'm not able to figure out why this is happening. I tried using bool conditions to do this, but failed.
2. If i play test this in my mobile.. Its only going on one direction. in my case its only zooming out continously though my zoom-in if-condition meets. But when playtesting in unity game window. The zoom in works when my mouse is out of the game-screen. Because its only working outside the game screen.This is the reason its not working in mobile as there is no space outside mobile display. Which i dont know why this is happening or dont know how to overcome this.

Let me know why! Im stuck at it for a long time and not getting any idea. Thanks <3

If Any doubt in question let me know. Sorry for a huge explanation. Just wanted to be very precise on the question. I have seen people suggesting zoom in zoom out through using FOV. But i wanna do it using translate or move the camera itself.

CodePudding user response：

So your problem here is on taking count on the screenToViewPort point. Instead just try this..

if (Input.GetMouseButtonDown(0))
{
     mInitialPosition = Input.mousePosition.y;
}
            
if (Input.GetMouseButton(0))
{
     mChangedPosition = Input.mousePosition.y;

     if (mChangedPosition == mInitialPosition)
     {
         return;
     }
     if (mChangedPosition < mInitialPosition)
     {
         Zoom((mZoomSpeed * -1f) * Time.deltaTime);
     }
     if (mChangedPosition > mInitialPosition)
     {
         Zoom(mZoomSpeed * Time.deltaTime);
     }
}
      
private void Zoom(float inZoomSpeed)
{
    transform.Translate(mCamRef.transform.position.z * inZoomSpeed * transform.forward);
}

Not sure how ScreenToViewport point works... But I guess this code should do the magic for you... Here I'm just straight away taking the mouse.y value on click and hold and did the same functions as you did and also telling it not to do anything when both the y values are same and return the function... So meaning that you already had everything in your code itself... Have a nice day