一个鼠标点击水波纹理shader

一张图片，通过鼠标点击产生水波纹理，shader比较简单，算法主要在C#那边，多线程优化计算

用下面shader创建一个材质，创建一个面片或Cube并挂上下面C#脚本，设置图片像素，默认是256*256，赋值材质图片纹理，运行，点击鼠标即可看到效果

shader

Shader "Zon/WaveTexture" {
Properties {
_MainTex ("水波纹理", 2D) = "" {}
}
SubShader {
pass{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"

sampler2D _MainTex;
sampler2D _WaveTex;

struct v2f {
float4 pos:POSITION;
float2 uv:TEXCOORD0;
};

v2f vert(appdata_full v)
{
v2f o;
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
o.uv = v.texcoord.xy;
return o;
}

fixed4 frag (v2f IN) : COLOR
{
float2 uv = tex2D(_WaveTex, IN.uv).xy;
uv = uv * 2 - 1; //把0~1转成-1~1
uv *= 0.025;

IN.uv += uv;

fixed4 color = tex2D(_MainTex, IN.uv);

return color;
}
ENDCG
}
}
}


C#脚本

using UnityEngine;
using System.Collections;
using System.Threading;

public class WaveTexture : MonoBehaviour {
public int waveWidth;
public int waveHeight;

float[,] waveA;
float[,] waveB;
Color[] colorBuffer;

Texture2D tex_uv;

bool isRun = true;
int sleepTime;

// Use this for initialization
void Start () {
waveA = new float[waveWidth, waveHeight];
waveB = new float[waveWidth, waveHeight];
colorBuffer = new Color[waveWidth * waveHeight];
tex_uv = new Texture2D (waveWidth, waveHeight);

GetComponent<Renderer> ().material.SetTexture ("_WaveTex", tex_uv);

Thread th = new Thread (new ThreadStart(ComputeWave));
th.Start ();
//Putpop ();
//PutDrop(64,64);
}

// Update is called once per frame
void Update () {
sleepTime = (int)(Time.deltaTime * 1000);
tex_uv.SetPixels (colorBuffer);
tex_uv.Apply ();

if (Input.GetMouseButton(0)) {
RaycastHit hit;
Ray ray = Camera.main.ScreenPointToRay (Input.mousePosition);
if (Physics.Raycast (ray, out hit)) {
Vector3 pos = transform.worldToLocalMatrix.MultiplyPoint(hit.point);//把世界坐标转换成图片像素坐标
//Debug.Log(pos);//pos = -0.5 ~ 0.5
int w = (int)((pos.x + 0.5) * waveWidth);
int h = (int)((pos.y + 0.5) * waveHeight);
PutDrop (w, h);
}
}
//ComputeWave ();
}

void Putpop()
{
//能量置1
waveA [waveWidth / 2, waveHeight / 2] = 1;//中间点
waveA [waveWidth / 2 - 1, waveHeight / 2] = 1;//左
waveA [waveWidth / 2 + 1, waveHeight / 2] = 1;//右
waveA [waveWidth / 2, waveHeight / 2 - 1] = 1;//下
waveA [waveWidth / 2, waveHeight / 2 + 1] = 1;//上
waveA [waveWidth / 2 - 1, waveHeight / 2 - 1] = 1;//左下
waveA [waveWidth / 2 - 1, waveHeight / 2 + 1] = 1;//左上
waveA [waveWidth / 2 + 1, waveHeight / 2 - 1] = 1;//右下
waveA [waveWidth / 2 + 1, waveHeight / 2 + 1] = 1;//右上
}

void PutDrop(int x, int y)
{
int radius = 20;
float dist;

for (int i = -radius; i <= radius; i++) {
for (int j = -radius; j <= radius; j++) {
if (((x + i >= 0) && (x + i < waveWidth - 1)) && ((y + j >= 0) && (y + j < waveHeight - 1))) {
dist = Mathf.Sqrt (i * i + j * j);
if (dist < radius)
waveA [x + i, y + j] = Mathf.Cos (dist * Mathf.PI / radius);
}
}
}
}

void ComputeWave()
{
while (isRun) {
for (int w = 1; w < waveWidth - 1; w++) {
for (int h = 1; h < waveHeight - 1; h++) {
//8个方向计算
waveB [w, h] = (waveA [w - 1, h] +
waveA [w + 1, h] +
waveA [w, h - 1] +
waveA [w, h + 1] +
waveA [w - 1, h - 1] +
waveA [w + 1, h - 1] +
waveA [w - 1, h + 1] +
waveA [w + 1, h + 1]) / 4 - waveB [w, h];

//能量限制
float value = waveB [w, h];
if (value > 1)
waveB [w, h] = 1;
if (value < -1)
waveB [w, h] = -1;

float offset_u = (waveB [w - 1, h] - waveB [w + 1, h]) / 2;
float offset_v = (waveB [w, h - 1] - waveB [w, h + 1]) / 2;

float r = offset_u / 2 + 0.5f;
float g = offset_v / 2 + 0.5f;

//tex_uv.SetPixel (w, h, new Color (r, g, 0));

colorBuffer [w + waveWidth * h] = new Color (r, g, 0);

waveB [w, h] -= waveB [w, h] * 0.0025f;//能量衰减计算

}
}

//tex_uv.Apply ();

float[,] temp = waveA;
waveA = waveB;
waveB = temp;

Thread.Sleep (sleepTime);
}
}

void OnDestroy()
{
isRun = false;
}
}