1.可以用於紋理的處理，也可用於模型顯示的處理（比如某件準備或者服飾未獲取的時候，灰化顯示）

　線上對比圖:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class TextureGrey : MonoBehaviour
{
    [SerializeField]
    UITexture tex = null;

    Texture2D tex2D = null;
    Vector3 grey = new Vector3(0.299f, 0.587f, 0.114f);  //灰化Shader中的灰度值，具體含義目前不是太清楚

    void Start()
    {
        tex2D = tex.mainTexture as Texture2D;
    }

    void Update()
    {
        if (Input.GetKeyUp(KeyCode.A))
        {
            //灰化
            Vector3 tempV3 = Vector3.zero;
            if (null != tex2D)
            {
                Color[] cols = tex2D.GetPixels();
                for (int i = 0, iMax = cols.Length; i < iMax; ++i)
                {
                    tempV3.Set(cols[i].r, cols[i].g, cols[i].b);
                    float dot = Vector3.Dot(tempV3, grey);
                    cols[i] = new Color(dot, dot, dot, cols[i].a);
                }
                tex2D = new Texture2D(tex2D.width, tex2D.height, TextureFormat.ARGB32, false);
                tex2D.SetPixels(cols);
                tex2D.Apply(false);         //實際上傳改變後的像素數據到顯卡上
                tex.mainTexture = tex2D as Texture;
                
            }
        }
    }
}

Unity 通過代碼簡單實現文理的灰化顯示