GetPixels

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
 
public class GetPixel : MonoBehaviour
{
    public RenderTexture rendTex;
    private Texture2D sourceTex;
 
    public GameObject prefab;
    public float offset = 1.2f;
    public float prefabScale = 5.0f;
 
    private int _width;
    private int _height;
 
    private Color[] pix;
    private List<GameObject> list;
    private List<Renderer> rendlist;
    private List<Transform> transformlist;
 
    private MaterialPropertyBlock properties; 
 
    void Start()
    { 
        sourceTex = GetRTPixels(rendTex);
        //소스 텍스트 크기 
        _width = sourceTex.width;
        _height = sourceTex.height;
        //픽셀 색깔 저장하기 
        pix = sourceTex.GetPixels(0, 0, _width, _height);
        //리스트 생성  
        list = new List<GameObject>();
        rendlist = new List<Renderer>();
        transformlist = new List<Transform>();
        properties = new MaterialPropertyBlock();
 
        //픽셀 큐브 생성 
        for (int w = 0; w < _width; w++)
        {
            for (int h = 0; h < _height; h++)
            {
                GameObject obj = Instantiate(prefab, new Vector3(w * offset, 0, h * offset), Quaternion.identity) as GameObject;
                list.Add(obj);
                transformlist.Add(obj.transform);
                Renderer rend = obj.GetComponent<Renderer>();
                rendlist.Add(rend);
 
                obj.transform.SetParent(transform);
            }
        }
 
        transform.rotation = Quaternion.Euler(180, -90, -90); //보드 회전하기 
    }
 
    private void Update()
    {
        sourceTex = GetRTPixels(rendTex); //실시간으로 texture받아오기 
        pix = sourceTex.GetPixels(0, 0, _width, _height); //pixel 받아오기 
 
        //픽셀 색상 적용 
        for (int i = 0; i < _width * _height; i++)
        {
            properties.SetColor("_Color", pix[i]);//gpuInstancing pixel Color값 받아오기 
            rendlist[i].SetPropertyBlock(properties); //gpuInstancing 사용 Color값 적용  
        }
 
        //pixel 애니메이션
        for (int i = 0; i < _width * _height; i++)
        {
            //화이트 제외 -> 사용하려면 아래 else로 묶어주기 
            //if(pix[i].r > .7f && pix[i].g > .7f && pix[i].b > .7f)
            //{
            //    transformlist[i].localScale = 
            //    new Vector3(1, Mathf.Lerp(list[i].transform.localScale.y, 0.1f, Time.deltaTime * 5.0f), 1);
            //}
 
            float color = pix[i].r + pix[i].g + pix[i].b;
 
            //색상 값 pingpong (균일)
            transformlist[i].localScale = 
            new Vector3(1, Mathf.PingPong(color * Time.time + .01f, color * prefabScale + 0.01f), 1);
 
            //색상 값 pingpong (비균일)
            //transformlist[i].localScale =
            //new Vector3(1, Mathf.PingPong(Time.time + .01f, color * prefabScale + 0.01f), 1);
 
            //속도 값 pingpong
            //transformlist[i].localScale = 
            //new Vector3(1, Mathf.PingPong(Time.time + color + 0.01f, prefabScale), 1);
 
            //색상 값 lerp - 색상 변형 영향 x
            //transformlist[i].localScale = 
            //new Vector3(1, Mathf.Lerp(list[i].transform.localScale.y, (color + 0.01f) * prefabScale, Time.deltaTime * 5.0f), 1);
        }
    }
 
    //renderTexture -> Texture2D로 전환 함수 
    static public Texture2D GetRTPixels(RenderTexture rt)
    {
        RenderTexture currentActiveRT = RenderTexture.active;
        RenderTexture.active = rt;
        Texture2D tex = new Texture2D(rt.width, rt.height);
        tex.ReadPixels(new Rect(0, 0, tex.width, tex.height), 0, 0);
        RenderTexture.active = currentActiveRT;
        return tex;
    }
 
}