2D Camera sizing and movement

Question

Apologies if this is a basic question, or been asked a 1,000 times in the past...

I'm new to Unity, and having problems understanding some of the basics to do with 2D cameras (orthographic), and while I've read a lot nothing has made me have that 'ah-ah!' moment yet.

What I'm trying to create is the following (camera position depicted by the box with the pink dashed line) - where the yellow filled boxes are made up of a whole bunch of sprites.

Overtime, the camera need to move left to right, and then bottom to top...

What my issue seems to be is understanding how I can get the camera to display all of the sprites - in other words, resize the camera view to fit the background sprite's height, and know when to stop the camera in order to start moving it up.

What I'd like to understand is how and why to solve this problem - it's the only way I'll learn!

Thanks

Kieron

Answer 1

I wrote a camera script that auto-zooms based on a transform's position and scale.

Attach the script below to your Camera. Then, create a GameObject, and set its position and size. Then link this gameobject to the "Area" public property of this camera script.

The "Area" GameObject can be adjusted at runtime, and should provide you with a mechanism to at least get you started on what you are attempting to do.

I put the logic inside of Update() to simplify, however, you will most likely want to move this in a function that you would call manually when a recalc needs to be done.

using UnityEngine;
using System.Collections;

public class CameraZoom : MonoBehaviour
{
    public Transform Area;

    public void Update()
    {
        float height = Area.localScale.y * 100;
        float width = Area.localScale.x * 100;

        float w = Screen.width / width;
        float h = Screen.height / height;

        float ratio = w / h;

        float size = (height / 2) / 100f;

        if (w < h)
            size /= ratio;

        Camera.main.orthographicSize = size;

        Vector2 position = Area.transform.position;

        Vector3 camPosition = position;
        Vector3 point = Camera.main.WorldToViewportPoint(camPosition);
        Vector3 delta = camPosition - Camera.main.ViewportToWorldPoint(new Vector3(0.5f, 0.5f, point.z));
        Vector3 destination = transform.position + delta;

        transform.position = destination;
    }

}