ScaleObjectToCamera.cs

//Author: Adilson Schmitt Junior ,aka SirGallifrey

//This script is just to show how you could resize a objet to fit a orthographic camera fustrum size.

using UnityEngine;
using System.Collections;

public class ScaleObjectToCamera : MonoBehaviour {

	public float widthPerc = 1.0f;
	public float heightPerc = 1.0f;
	
	private GameObject target;
	
	private Camera camera;
	
	private CameraSize _cameraSize;
	
	void Start () {
		_cameraSize = new CameraSize();
		camera = GetComponent<Camera>();
		target = GameObject.CreatePrimitive(PrimitiveType.Quad);
		target.transform.position = transform.position;
		target.transform.Translate(new Vector3(0,0,1));
		
	}
	
	// Update is called once per frame
	void Update () {
		//TODO: Fazer isso dentro do update não é interessante por que terão muitos resizes desnecessários. o legal é dar o resize somente quando o tamanho da tela mudar.
		ResizeTarget();
	}
	
	void ResizeTarget() {
		Bounds bounds = target.GetComponent<MeshFilter>().mesh.bounds;
		
		target.transform.localScale = new Vector3(cameraSize.width*widthPerc/bounds.size.x, cameraSize.height*heightPerc/bounds.size.y);
	}

	public CameraSize cameraSize {
		get {
			_cameraSize.height = 2 * camera.orthographicSize;
			_cameraSize.width = _cameraSize.height * camera.aspect;  
			return _cameraSize;
		}
	}
}

public class CameraSize {
	public float height;
	public float width;
}