Unity shader實現移動端模擬深度水效果

本文實例為大家分享了Unity shader實現移動端模擬深度水的具體代碼，供大家參考，具體內容如下
描述：
在網上看到很多效果很好的水，比如根據水的深度，顏色有深淺變化，能讓水變得更真實，但是又會涉及到比較複雜的計算，在移動端上面還是有些吃力的。
最近研究了一下，想在移動端上面模擬這樣的效果 ：
1 水的深淺透明度變化
2 水的深淺顏色變化
3 水上的陰影模擬（大面積的水通過烘焙比較浪費烘焙圖）
根據上面的3點，可以通過一張黑白圖的rg通道來實現深淺以及陰影的模擬 效果如下
如圖，淺色的偏綠，深色的偏藍 ，顏色可以手動調節，左邊為陰影位置
代碼如下：
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 

//模擬燈光顏色

 _LightColorSelf ("LightColorSelf",Color) = (1,1,1,1) 

//模擬燈光方向 

_LightDir ("LightDir",vector) = (0,1,0,0) 

//高光強度 _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); 

//視向量（世界空間） 

o.worldView = -normalize(worldPos - _WorldSpaceCameraPos); o.position = UnityObjectToClipPos(v.vertex); 

//uv動畫 

o.tilingAndOffset.z =frac( _Time.x * _WaveSpeed);

//frac :返回標量或矢量的小數 

o.tilingAndOffset.xy = worldPos.xz*_Tiling; o.alphaUV = v.texcoord; 

//求世界法線三件套

 float3 normal =normalize( UnityObjectToWorldNormal(v.normal)); float3 tangentDir = normalize( mul( unity_ObjectToWorld, float4( v.tangent.xyz, 0.0 ) ).xyz );

//切線空間轉化為世界空間 

float3 bitangentDir = normalize(cross(normal, tangentDir) * v.tangent.w);//切線 法線 計算副切線 o.tangentTransform = float3x3( tangentDir, bitangentDir, normal); return o; } float4 Frag(v2f i):COLOR { 

//法線採樣 fixed3 BumpMap01 = UnpackNormal(tex2D(_WaterTex,i.tilingAndOffset.xy + i.tilingAndOffset.z )); fixed3 BumpMap02 = UnpackNormal(tex2D(_WaterTex,i.tilingAndOffset.xy*1.1 - i.tilingAndOffset.z)); 

//兩張法線相混合 

//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為模擬燈光 

//高光 

float dotSpecular = dot(worldNormal, normalize( i.worldView+_LightDir.xyz)); fixed3 specularReflection = pow(saturate(dotSpecular), _SpecularRatio)*_specularLight; 

//通道貼圖採樣 

fixed4 alphaTex = tex2D (_AlphaTex,i.alphaUV);

 //模擬燈光的顏色 * 漫反射係數= 基礎水的顏色 

fixed4 col =_LightColorSelf*2 * saturate (LdotN) ; 

//用alpha貼圖的r通道來模擬水的深淺的顏色，白色為深色，黑色為淺色 ，同時乘以想要的顏色

 col.rgb = col.rgb * alphaTex.r *_inSideColor * _inSideLight + col.rgb * (1-alphaTex.r) * _outSideColor *_outSideLight + specularReflection;

 //控制透明度，根據alpha的r通道 來控制深淺的透明度，深色的透明度小 淺色的透明度大 

col.a = _Alpha * alphaTex.r; 

//手動繪製陰影 用alpha貼圖的g通道 跟col相乘 來模擬陰影 

alphaTex.g = saturate(alphaTex.g + _shadowLight); 

col.rgb *= alphaTex.g; return col; } ENDCG } } FallBack "Diffuse" }