Unity shader实现移动端模拟深度水效果

本文实例为大家分享了unity shader实现移动端模拟深度水的具体代码，供大家参考，具体内容如下

描述：

在网上看到很多效果很好的水，比如根据水的深度，颜色有深浅变化，能让水变得更真实，但是又会涉及到比较复杂的计算，在移动端上面还是有些吃力的。

最近研究了一下，想在移动端上面模拟这样的效果 ：

1 水的深浅透明度变化

2 水的深浅颜色变化

3 水上的阴影模拟（大面积的水通过烘焙比较浪费烘焙图）

根据上面的3点，可以通过一张黑白图的rg通道来实现深浅以及阴影的模拟 效果如下

如图，浅色的偏绿，深色的偏蓝 ，颜色可以手动调节，左边为阴影位置

代码如下：

shader "game_xxx/whater"
{
 properties 
 {
 _watertex ("normal map (rgb), foam (a)", 2d) = "white" {}
 _alphatex("alphatex", 2d) = "black" {}
 _shadowlight ("shadowlight",range(0,1)) = 0
 _tiling ("wave scale", range(0.00025, 0.007)) = 0.25
 _wavespeed("wave speed", float) = 0.4
 _specularratio ("specular ratio", range(10,500)) = 200
 _outsidecolor("outsidecolor",color) = (0,0,0,0)
 _outsidelight("outsidelight",range(0,10))=1
 _insidecolor("insidecolor",color) = (0,0,0,0)
 _insidelight("intsidelight",range(0,10))=1
 _alpha("alpha",range(0,1)) = 1
 //模拟灯光颜色
 _lightcolorself ("lightcolorself",color) = (1,1,1,1)
 //模拟灯光方向
 _lightdir ("lightdir",vector) = (0,1,0,0)
 //高光强度
 _specularlight("specularlight",range(0.1,2)) =1 
 }
 
 subshader { 
 tags {
 "queue"="transparent-200"
 "rendertype"="transparent" 
 "ignoreprojector" = "true"
 "lightmode" = "forwardbase"
 }
 lod 250
 pass
 {
 
 zwrite off
 blend srcalpha oneminussrcalpha
 cgprogram
 
 #pragma vertex vert
 #pragma fragment frag
 #include "unitycg.cginc"
 
 float _tiling;
 float _wavespeed;
 float _specularratio;
 sampler2d _watertex;
 sampler2d _alphatex;
 float4 _lightcolorself;
 float4 _lightdir;
 float4 _outsidecolor;
 float _outsidelight;
 float4 _insidecolor;
 float _insidelight;
 float _shadowlight;
 float _specularlight;
 float _alpha;
 
 struct v2f
 {
 float4 position : position;
 float3 worldview : texcoord0;
 float3 tilingandoffset:texcoord2;
 float3x3 tangenttransform:texcoord4; 
 float2 alphauv :texcoord7;
 
 };
 
 
 
 v2f vert(appdata_full v)
 {
 v2f o;
 float4 worldpos = mul(unity_objecttoworld, v.vertex);
 //视向量（世界空间）
 o.worldview = -normalize(worldpos - _worldspacecamerapos);
 o.position = unityobjecttoclippos(v.vertex);
 //uv动画
 o.tilingandoffset.z =frac( _time.x * _wavespeed);//frac :返回标量或矢量的小数
 o.tilingandoffset.xy = worldpos.xz*_tiling;
 o.alphauv = v.texcoord;
 //求世界法线三件套 
 float3 normal =normalize( unityobjecttoworldnormal(v.normal)); 
    float3 tangentdir = normalize( mul( unity_objecttoworld, float4( v.tangent.xyz, 0.0 ) ).xyz );//切线空间转化为世界空间 
    float3 bitangentdir = normalize(cross(normal, tangentdir) * v.tangent.w);//切线 法线 计算副切线 
 
 o.tangenttransform = float3x3( tangentdir, bitangentdir, normal); 
 return o;
 }
 
 float4 frag(v2f i):color
 {
 
  
 
  //法线采样
  fixed3 bumpmap01 = unpacknormal(tex2d(_watertex,i.tilingandoffset.xy + i.tilingandoffset.z ));
  fixed3 bumpmap02 = unpacknormal(tex2d(_watertex,i.tilingandoffset.xy*1.1 - i.tilingandoffset.z));
  //两张法线相混合
  //fixed3 n1 =saturate( normalize(mul( bumpmap01.rgb, i.tangenttransform )));
  //fixed3 n2 =saturate( normalize(mul( bumpmap02.rgb, i.tangenttransform )));
  //fixed3 worldnormal = n1 - float3(n2.x,0,n2.z);
 
  fixed3 n1 = normalize(mul( bumpmap01.rgb, i.tangenttransform ));
  fixed3 n2 = normalize(mul( bumpmap02.rgb, i.tangenttransform ));
  fixed3 worldnormal = n1*0.5 +n2*0.5;
 
 
 
 
  float ldotn = dot(worldnormal, _lightdir.xyz); //_lightdir为模拟灯光
 
 
  //高光 
  float dotspecular = dot(worldnormal, normalize( i.worldview+_lightdir.xyz));
  fixed3 specularreflection = pow(saturate(dotspecular), _specularratio)*_specularlight;
 
 
  //通道贴图采样
  fixed4 alphatex = tex2d (_alphatex,i.alphauv);
  //模拟灯光的颜色 * 漫反射系数= 基础水的颜色
  fixed4 col =_lightcolorself*2 * saturate (ldotn) ;
  //用alpha贴图的r通道来模拟水的深浅的颜色，白色为深色，黑色为浅色 ，同时乘以想要的颜色
  col.rgb = col.rgb * alphatex.r *_insidecolor * _insidelight + col.rgb * (1-alphatex.r) * _outsidecolor *_outsidelight + specularreflection;
 
  //控制透明度，根据alpha的r通道 来控制深浅的透明度，深色的透明度小 浅色的透明度大
  col.a = _alpha * alphatex.r;
 
  //手动绘制阴影 用alpha贴图的g通道 跟col相乘 来模拟阴影 
  alphatex.g = saturate(alphatex.g + _shadowlight);
  col.rgb *= alphatex.g;
  return col;
 }
  endcg 
  } 
 }
 
 fallback "diffuse"
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。