A simple implementation of an infinite zooming technique a la Zoom Quilt (http://zoomquilt.org) for Unity 3d. Takes the player's position on the z axis and adjusts the cards to match. The cards should be rendered by an orthographic camera

ZoomCardController

using UnityEngine;
using System.Collections;

public class ZoomCardController : MonoBehaviour {
  
	/** Collection of zooming cards to be displayed. */
	public GameObject[] Cards;
	
	/** Distance player travels between cards. */
	public float DistanceBetweenCards = 10;
	
	
	void LateUpdate () {
		
		// Locate player in world space.
		Vector3 p = PlayerController.Instance.transform.position;
		
		// Determine current travel fraction along the z-axis.
		// Varies from [0..1] as the player moves between successive cards.
		float t = (p.z % DistanceBetweenCards) / DistanceBetweenCards;
		if (t < 0)
			t += 1;
		
		// Bias the fraction to smooth out view jerkiness.
		// Not exactly sure why this helps, but it does.. :)
		t = Mathf.Pow(t, 1.3f);
		
		// Set up each card for current travel fraction.
		int n = Cards.Length;
		for (int i = 0; i<n; i++)
			UpdateCard(Cards[i], i, n, t);
		
		// Adjust alpha of the smallest card.
		// The smallest card fades in as you get closer to it.
		Cards[0].renderer.material.color = new Color(1, 1, 1, t);
	}
	
	private void UpdateCard(GameObject card, int i, int n, float t)
	{
		float divisor = Mathf.Pow(3, n - 1);
		float minZoom = Mathf.Pow(3, i) / divisor;
		float maxZoom = Mathf.Pow(3, i + 1) / divisor;
		float s = Mathf.Lerp(minZoom, maxZoom, t);
		card.transform.localScale = new Vector3(s, s, s);
	}
}