unity-keep-quad-texture-scale

using UnityEngine;
using System.Collections;

[ExecuteInEditMode]
public class QuadTextureScaler : MonoBehaviour
{
    private Renderer rend;
    private float textureWidthInUnits;
    private float textureHeightInUnits;
    private float pixelsPerUnit;

	private void Start() {
        rend = GetComponent<Renderer>();

        Texture texture = rend.material.mainTexture;

        pixelsPerUnit = Screen.height / (Camera.main.orthographicSize * 2);

        textureWidthInUnits = texture.width / pixelsPerUnit;
        textureHeightInUnits = texture.height / pixelsPerUnit;
    }
	
	private void Update () {
        rend.material.mainTextureScale = new Vector2(transform.localScale.x / textureWidthInUnits, transform.localScale.y / textureHeightInUnits);
    }
}