Scale Sprite to Fullscreen: Perspective Camera

Unity Engine
1

Hi Guys,

I’m trying to scale a image (UI 4.6 ) to fit the screen width/height of the viewport.

I have existing code to do this with the orthographic camera:

    public bool SetInitialSize()
    {
        SpriteRenderer sr = GetComponent<SpriteRenderer>();

        if (sr)
        {
            Camera cam;
            if (cam = GameObject.Find("MapViewCamera").GetComponent<Camera>())
            {
                float worldScreenHeight = (float)(cam.orthographicSize * 2.0);
                float worldScreenWidth = worldScreenHeight / Screen.height * Screen.width;
                float newLocalScale = (worldScreenWidth / sr.sprite.bounds.size.x);

                transform.localScale = new Vector3(newLocalScale, newLocalScale, 1);
                SetScaleClamp(transform.localScale);

                Vector3 position;
                position.x = cam.transform.position.x - (sr.bounds.size.x * 0.5f);
                position.y = cam.transform.position.y - (sr.bounds.size.y * 0.5f);
                position.z = transform.position.z;
                transform.position = position;
            }
            else
            {
                Debug.Log("MapHandler::SetInitialSize() - Camera not found as parent to Map Object!");
                return false;
            }
        }
        else
        {
            Debug.Log("MapHandler::SetInitialSize() - SpriteRenderer Component not found!");
            return false;
        }
        return true;
    }

However I have no idea about the maths for doing this with a perspective camera. I’ve google’d around, and people only seem to mention orthographic. I understand it’d be based by distance from the camera, however what’s the equation? Does anyone have sample code?

Thanks!

2

Well if it is ui 4.6 then it is on canvas which is on camera and it doesn’t matter type of camera or size right?

3

Yeah that sounds right to me phoda… The problem is how do I calculate from there?

The only measurements I see I can take are orthographicSize, pixelHeight, and Screen.Height… When I put them into the equation, like so:

if (image)
        {

            float worldScreenHeight = (float)(Screen.height);
            float worldScreenWidth = worldScreenHeight / Screen.height * Screen.width;
            float newLocalScale = (worldScreenWidth / image.sprite.bounds.size.x);
            transform.localScale = new Vector3(newLocalScale, newLocalScale, 1);
        }

The image ends up being about x10 the size of the viewport…

Any thoughts?

Thanks!

4

Seems like a cheat, but for anyone curious about how I got around this. I simply added a AspectRatioFitter from the layout section to a parent of the Image. I then set the aspect ratio high enough in width that it’d always appear fully no matter what the screen size… Although it’s not mathematically flush, it works…

5

hehe there ar no cheats in game making. If it works its good if not then find another way

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