Unity Shader 学习笔记(十二) 创建程序纹理贴图

Unity Shader 学习笔记(十二) 创建程序纹理贴图

创建一个脚本 附加到一个游戏体上

using UnityEngine;
using System.Collections;

public class ProceduralTexture : MonoBehaviour
{
#region Public Variables
    //纹理的宽高
    public int widthHeight = 512;
    //程序生成的纹理
    public Texture2D generaterdTexture;
#endregion

#region Private Variables
    private Material currentMaterial;
    private Vector2 centerPosition;
#endregion


	// Use this for initialization
	void Start () {
	
        if (!currentMaterial)
        {
            currentMaterial = transform.renderer.sharedMaterial;
            if (!currentMaterial)
            {
                Debug.LogWarning("Cannot find a material on : " + transform.name);
            }
            
        }

        if (currentMaterial)
        {
            centerPosition = new Vector2(0.5f, 0.5f);
            generaterdTexture = GenerateParabola();

            //设置纹理
            currentMaterial.SetTexture("_MainTex",generaterdTexture);
        }
        
        
	}
    private Texture2D GenerateParabola()
    {
        //创建一个新的纹理
        Texture2D proceduralTexture = new Texture2D(widthHeight, widthHeight);

        //获取当前纹理的中心点
        Vector2 centerPixelPosition = centerPosition * widthHeight;

        //循环遍历纹理的宽高 , 来为每个像素点赋值
        for (int x = 0; x < widthHeight; x++)
        {
            for (int y = 0; y < widthHeight; y++)
            {
                //Get the distance from the center of the texture to
                //our currently selected pixel
                Vector2 currentPosition = new Vector2(x, y);
                //当前像素点到中心点的距离 / 纹理宽高的一半
                float pixelDistance = Vector2.Distance(currentPosition, centerPixelPosition) / (widthHeight * 0.5f);
                // Mathf.Abs : 取绝对值   Mathf.Clamp  0-1
                pixelDistance = Mathf.Abs(1 - Mathf.Clamp(pixelDistance, 0f, 1f));
                pixelDistance = (Mathf.Sin(pixelDistance * 30.0f) * pixelDistance);

                //you can also do some more advanced vector calculations to achieve
                //other types of data about the model itself and its uvs and
                //pixels

                //以中心为原点 获取到当前像素点的向量
                Vector2 pixelDirection = centerPixelPosition - currentPosition;
                pixelDirection.Normalize();

                //当前像素点向量 和 上左右三个方向的向量之间的夹角
                float rightDirection = Vector2.Angle(pixelDirection, Vector3.right) / 360;
                float leftDirection = Vector2.Angle(pixelDirection, Vector3.left) / 360;
                float upDirection = Vector2.Angle(pixelDirection, Vector3.up) / 360;

                
                //确保像素点的颜色值在 (0,1) 之间

                //Create a new color value based off of our
                //Color pixelColor = new Color(Mathf.Max(0.0f, rightDirection),Mathf.Max(0.0f, leftDirection), Mathf.Max(0.0f,upDirection), 1f);
                Color pixelColor = new Color(pixelDistance, pixelDistance, pixelDistance, 1.0f);
                //Color pixelColor = new Color(rightDirection, leftDirection, upDirection, 1.0f);
                proceduralTexture.SetPixel(x, y, pixelColor);

                //将中间的像素点设置成红色
                if (x == widthHeight / 2 || y == widthHeight / 2)
                {
                    Color middlePixelColor = new Color(1, 0, 0, 1.0f);
                    proceduralTexture.SetPixel(x, y, middlePixelColor);
                }
            }
        }
        //Finally force the application of the new pixels to the texture
        proceduralTexture.Apply();

        //return the texture to the main program.
        return proceduralTexture;
    }
	
	// Update is called once per frame
	void Update () {
	
	}
}