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
