Unity Shader实现水波纹效果

本文实例为大家分享了Unity Shader实现水波纹的具体代码，供大家参考，具体内容如下

效果：

Shader代码：

Shader "Custom/shuibowen"{
Properties{
_MainTex("Base (RGB)",2D)="white"{}
_distanceFactor("Distancefactor",float)=1
_timeFactor("time factor",float)=2
_totalFactor("total factor",float)=3
_waveWidth("wave width",float)=4
_curWaveDis("curwave dis",float)=5
_startPos("star pos",Vector) = (1,1,1,1)
_MainTex_TexelSize("Maintex_texelSize",vector)=(1,1,1,1)
}
CGINCLUDE
#include "UnityCG.cginc"
uniform sampler2D _MainTex;
float4 _MainTex_TexelSize;
uniform float _distanceFactor;
uniform float _timeFactor;
uniform float _totalFactor;
uniform float _waveWidth;
uniform float _curWaveDis;
uniform float4 _startPos;
fixed4 frag(v2f_img i) : SV_Target
{
//DX下纹理坐标反向问题
#if UNITY_UV_STARTS_AT_TOP
if (_MainTex_TexelSize.y < 0)
_startPos.y = 1 - _startPos.y;
#endif
//计算uv到中间点的向量(向外扩，反过来就是向里缩)
float2 dv = _startPos.xy - i.uv;
//按照屏幕长宽比进行缩放
dv = dv * float2(_ScreenParams.x / _ScreenParams.y, 1);
//计算像素点距中点的距离
float dis = sqrt(dv.x * dv.x + dv.y * dv.y);
//用sin函数计算出波形的偏移值factor
//dis在这里都是小于1的，所以我们需要乘以一个比较大的数，比如60，这样就有多个波峰波谷
//sin函数是（-1，1）的值域，我们希望偏移值很小，所以这里我们缩小100倍，据说乘法比较快,so...
float sinFactor = sin(dis * _distanceFactor + _Time.y * _timeFactor) * _totalFactor * 0.01;
//距离当前波纹运动点的距离，如果小于waveWidth才予以保留，否则已经出了波纹范围，factor通过clamp设置为0
float discardFactor = clamp(_waveWidth - abs(_curWaveDis - dis), 0, 1) / _waveWidth;
//归一化
float2 dv1 = normalize(dv);
//计算每个像素uv的偏移值
float2 offset = dv1 * sinFactor * discardFactor;
//像素采样时偏移offset
float2 uv = offset + i.uv;
return tex2D(_MainTex, uv);
}
ENDCG
SubShader
{
Pass
{
ZTest Always
Cull Off
ZWrite Off
Fog { Mode off }

CGPROGRAM
#pragma vertex vert_img
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
ENDCG
}
}
Fallback off
}

C#代码：

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

public class WaterWaveEffect : PostEffectsBase {
//距离系数
public float distanceFactor = 60.0f;
//时间系数
public float timeFactor = -30.0f;
//sin函数结果系数
public float totalFactor = 1.0f;

//波纹宽度
public float waveWidth = 0.3f;
//波纹扩散的速度
public float waveSpeed = 0.3f;

private float waveStartTime;
private Vector4 startPos = new Vector4(0.5f, 0.5f, 0, 0);
public Material _Material;

void OnRenderImage(RenderTexture source, RenderTexture destination)
{
//计算波纹移动的距离，根据enable到目前的时间*速度求解
float curWaveDistance = (Time.time - waveStartTime) * waveSpeed;
//设置一系列参数
_Material.SetFloat("_distanceFactor", distanceFactor);
_Material.SetFloat("_timeFactor", timeFactor);
_Material.SetFloat("_totalFactor", totalFactor);
_Material.SetFloat("_waveWidth", waveWidth);
_Material.SetFloat("_curWaveDis", curWaveDistance);
_Material.SetVector("_startPos", startPos);
Graphics.Blit(source, destination, _Material);
}

void Update()
{
if (Input.GetMouseButton(0))
{
Vector2 mousePos = Input.mousePosition;
//将mousePos转化为（0，1）区间
startPos = new Vector4(mousePos.x / Screen.width, mousePos.y / Screen.height, 0, 0);
waveStartTime = Time.time;
}

}
}

新建一个材质球，选择此shader，并赋值给这个脚本，点击屏幕即可看到效果

以上就是本文的全部内容，希望对大家的学习有所帮助

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