先看下效果：
這個海浪除了正常的座標點週期性變化之外，這個拍岸的浪花和靠近陸地部分的深度很吸引我。果斷找到這個shader做了下分析。發現拍岸浪和顏色，都是根據水深計算的。而水深是根據場景的深度計算的。
COMPUTE_EYEDEPTH(o.sPos.z);//將z值賦值爲點到視點的深度。這行先計算水面的視深度
float sceneZ = SAMPLE_DEPTH_TEXTURE_PROJ(_CameraDepthTexture, UNITY_PROJ_COORD(IN.sPos));這裏計算場景深度，用這兩個對比，今兒算出水深。由於水是transparent的，所以不用寫入shadow，就是用這個技巧來計算的。
下面直接上shader和shader裏的註釋了。
// Upgrade NOTE: upgraded instancing buffer 'Props' to new syntax.
// Toony Colors Pro+Mobile 2
// (c) 2014-2017 Jean Moreno
Shader "Toony Colors Pro 2/Examples/Cat Demo/Water"
{
Properties
{
[TCP2HelpBox(Warning,Make sure that the Camera renders the depth texture for this material to work properly.You can use the script __TCP2_CameraDepth__ for this.)]
[TCP2HeaderHelp(BASE, Base Properties)]
//TOONY COLORS
_HColor("Highlight Color", Color) = (0.6,0.6,0.6,1.0)
_SColor("Shadow Color", Color) = (0.3,0.3,0.3,1.0)
//DIFFUSE
_MainTex("Main Texture (RGB)", 2D) = "white" {}
[TCP2Separator]
//TOONY COLORS RAMP
_RampThreshold("Ramp Threshold", Range(0,1)) = 0.5
_RampSmooth("Ramp Smoothing", Range(0.001,1)) = 0.1
[TCP2Separator]
[TCP2HeaderHelp(WATER)]
_Color("Water Color", Color) = (0.5,0.5,0.5,1.0)
[Header(Depth Color)]
_DepthColor("Depth Color", Color) = (0.5,0.5,0.5,1.0)
[PowerSlider(5.0)] _DepthDistance("Depth Distance", Range(0.01,3)) = 0.5
[Header(Foam)]
_FoamSpread("Foam Spread", Range(0.01,5)) = 2
_FoamStrength("Foam Strength", Range(0.01,1)) = 0.8
_FoamColor("Foam Color (RGB) Opacity (A)", Color) = (0.9,0.9,0.9,1.0)
[NoScaleOffset]
_FoamTex("Foam (RGB)", 2D) = "white" {}
_FoamSmooth("Foam Smoothness", Range(0,0.5)) = 0.02
_FoamSpeed("Foam Speed", Vector) = (2,2,2,2)
[Header(Vertex Waves Animation)]
_WaveSpeed("Speed", Float) = 2
_WaveHeight("Height", Float) = 0.1
_WaveFrequency("Frequency", Range(0,10)) = 1
[Header(UV Waves Animation)]
_UVWaveSpeed("Speed", Float) = 1
_UVWaveAmplitude("Amplitude", Range(0.001,0.5)) = 0.05
_UVWaveFrequency("Frequency", Range(0,10)) = 1
[TCP2Separator]
[TCP2HeaderHelp(RIM, Rim)]
//RIM LIGHT
_RimColor("Rim Color", Color) = (0.8,0.8,0.8,0.6)
_RimMin("Rim Min", Range(0,1)) = 0.5
_RimMax("Rim Max", Range(0,1)) = 1.0
[TCP2Separator]
//Avoid compile error if the properties are ending with a drawer
[HideInInspector] __dummy__("unused", Float) = 0
}
SubShader
{
Tags {"Queue" = "Geometry" "RenderType" = "Opaque"}
CGPROGRAM
#pragma surface surf ToonyColorsWater keepalpha vertex:vert nolightmap
#pragma target 3.0
//================================================================
// VARIABLES
fixed4 _Color;
sampler2D _MainTex;
float4 _MainTex_ST;
sampler2D_float _CameraDepthTexture;
fixed4 _DepthColor;
half _DepthDistance;
half4 _FoamSpeed;
half _FoamSpread;
half _FoamStrength;
sampler2D _FoamTex;
fixed4 _FoamColor;
half _FoamSmooth;
half _WaveHeight;
half _WaveFrequency;
half _WaveSpeed;
half _UVWaveAmplitude;
half _UVWaveFrequency;
half _UVWaveSpeed;
fixed4 _RimColor;
fixed _RimMin;
fixed _RimMax;
struct Input
{
half2 texcoord;
half3 viewDir;
half2 sinAnim;
float4 sPos;
};
//================================================================
// CUSTOM LIGHTING
//Lighting-related variables
half4 _HColor;
half4 _SColor;
half _RampThreshold;
half _RampSmooth;
// Instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
// See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
// #pragma instancing_options assumeuniformscaling
UNITY_INSTANCING_BUFFER_START(Props)
// put more per-instance properties here
UNITY_INSTANCING_BUFFER_END(Props)
//Custom SurfaceOutput
struct SurfaceOutputWater
{
half atten;
fixed3 Albedo;
fixed3 Normal;
fixed3 Emission;
fixed Alpha;
};
inline half4 LightingToonyColorsWater(inout SurfaceOutputWater s, half3 viewDir, UnityGI gi)
{
half3 lightDir = gi.light.dir;
#if defined(UNITY_PASS_FORWARDBASE)
half3 lightColor = _LightColor0.rgb;
half atten = s.atten;
#else
half3 lightColor = gi.light.color.rgb;
half atten = 1;
#endif
s.Normal = normalize(s.Normal);
fixed ndl = max(0, dot(s.Normal, lightDir));
#define NDL ndl
#define RAMP_THRESHOLD _RampThreshold
#define RAMP_SMOOTH _RampSmooth
fixed3 ramp = smoothstep(RAMP_THRESHOLD - RAMP_SMOOTH * 0.5, RAMP_THRESHOLD + RAMP_SMOOTH * 0.5, NDL);
#if !(POINT) && !(SPOT)
ramp *= atten;
#endif
#if !defined(UNITY_PASS_FORWARDBASE)
_SColor = fixed4(0,0,0,1);
#endif
_SColor = lerp(_HColor, _SColor, _SColor.a); //Shadows intensity through alpha
ramp = lerp(_SColor.rgb, _HColor.rgb, ramp);
fixed4 c;
c.rgb = s.Albedo * lightColor.rgb * ramp;
c.a = s.Alpha;
#ifdef UNITY_LIGHT_FUNCTION_APPLY_INDIRECT
c.rgb += s.Albedo * gi.indirect.diffuse;
#endif
return c;
}
void LightingToonyColorsWater_GI(inout SurfaceOutputWater s, UnityGIInput data, inout UnityGI gi)
{
gi = UnityGlobalIllumination(data, 1.0, s.Normal);
gi.light.color = _LightColor0.rgb; //remove attenuation
s.atten = data.atten; //transfer attenuation to lighting function
}
//================================================================
// VERTEX FUNCTION
struct appdata_tcp2
{
float4 vertex : POSITION;
float3 normal : NORMAL;
float4 texcoord : TEXCOORD0;
float4 texcoord1 : TEXCOORD1;
float4 texcoord2 : TEXCOORD2;
#if UNITY_VERSION >= 550
UNITY_VERTEX_INPUT_INSTANCE_ID
#endif
};
#define TIME (_Time.y)
void vert(inout appdata_tcp2 v, out Input o)
{
UNITY_INITIALIZE_OUTPUT(Input, o);
//Main texture UVs
float3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
half2 mainTexcoords = worldPos.xz * 0.1;//因爲水面的尺寸是10.不乘以0.1就會導致repeat。比較難看
o.texcoord.xy = TRANSFORM_TEX(mainTexcoords.xy, _MainTex);//根據texture的縮放
half2 x = ((v.vertex.xy + v.vertex.yz) * _UVWaveFrequency) + (TIME.xx * _UVWaveSpeed);
o.sinAnim = x;
//vertex waves
float3 _pos = worldPos.xyz * _WaveFrequency;
float _phase = TIME * _WaveSpeed;
half4 vsw_offsets = half4(1.0, 2.2, 0.6, 1.3);
half4 vsw_ph_offsets = half4(1.0, 1.3, 2.2, 0.4);
half4 waveXZ = sin((_pos.xxzz * vsw_offsets) + (_phase.xxxx * vsw_ph_offsets));
// float waveFactorX = (waveXZ.x + waveXZ.y) * _WaveHeight / 2;
// float waveFactorZ = (waveXZ.z + waveXZ.w) * _WaveHeight / 2;
float waveFactorX = dot(waveXZ.xy, 1) * _WaveHeight / 2;
float waveFactorZ = dot(waveXZ.zw, 1) * _WaveHeight / 2;
#define VSW_STRENGTH 1
v.vertex.y += (waveFactorX + waveFactorZ) * VSW_STRENGTH;
half4 waveXZn = cos((_pos.xxzz * vsw_offsets) + (_phase.xxxx * vsw_ph_offsets)) * (vsw_offsets / 2);
float xn = -_WaveHeight * (waveXZn.x + waveXZn.y);
float zn = -_WaveHeight * (waveXZn.z + waveXZn.w);
v.normal = normalize(float3(xn, 1, zn));
float4 pos = UnityObjectToClipPos(v.vertex);
o.sPos = ComputeScreenPos(pos);
COMPUTE_EYEDEPTH(o.sPos.z);//將z值賦值爲點到視點的深度
}
//================================================================
// SURFACE FUNCTION
void surf(Input IN, inout SurfaceOutputWater o)
{
half2 uvDistort = ((sin(0.9*IN.sinAnim.xy) + sin(1.33*IN.sinAnim.xy + 3.14) + sin(2.4*IN.sinAnim.xy + 5.3)) / 3) * _UVWaveAmplitude;
IN.texcoord.xy += uvDistort.xy;
half ndv = saturate(dot(IN.viewDir, o.Normal));//法線和視角的點乘。
fixed4 mainTex = tex2D(_MainTex, IN.texcoord.xy);
float sceneZ = SAMPLE_DEPTH_TEXTURE_PROJ(_CameraDepthTexture, UNITY_PROJ_COORD(IN.sPos));//此點的深度值,這裏是關鍵。
//SAMPLE_DEPTH_TEXTURE_PROJ這個函數使用的是投影渲染獲取的深度，這個水不投影，因爲最後一行的 Fallback "Diffuse"是註釋掉的，
//所以算深度的時候不包括水。partZ是水的深度值。兩個差值，就可以算出水的深度。
//這裏本來發現一個小問題，就是給陸地的fallback關閉，發現還是能正常渲染。後來發現，surface shader中使用addshadow也是會產生陰影和深度通道的。
//如果給這兩個都關閉的話，就會沒有深度不同的效果了。
//具體參考https://docs.unity3d.com/Manual/SL-CameraDepthTexture.html頁面的DepthTextureMode.Depth texture這小結。總算搞明白了。
//根據這個水深，再去設置水的顏色和波浪
if (unity_OrthoParams.w > 0)
{
//orthographic camera
#if defined(UNITY_REVERSED_Z)
sceneZ = 1.0f - sceneZ;
#endif
sceneZ = (sceneZ * _ProjectionParams.z) + _ProjectionParams.y;
}
else
//perspective camera
sceneZ = LinearEyeDepth(sceneZ);
float partZ = IN.sPos.z;
float depthDiff = abs(sceneZ - partZ);//這裏算出了水的深度
depthDiff *= ndv * 2;
//Depth-based foam
half2 foamUV = IN.texcoord.xy;
foamUV.xy += TIME.xx*_FoamSpeed.xy*0.05;
fixed4 foam = tex2D(_FoamTex, foamUV);
foamUV.xy += TIME.xx*_FoamSpeed.zw*0.05;
fixed4 foam2 = tex2D(_FoamTex, foamUV);
foam = (foam + foam2) / 2;
float foamDepth = saturate(_FoamSpread * depthDiff);
half foamTerm = (smoothstep(foam.r - _FoamSmooth, foam.r + _FoamSmooth, saturate(_FoamStrength - foamDepth)) * saturate(1 - foamDepth)) * _FoamColor.a;
//Alter color based on depth buffer (soft particles technique)
mainTex.rgb = lerp(_DepthColor.rgb, mainTex.rgb, saturate(_DepthDistance * depthDiff)); //N.V corrects the result based on view direction (depthDiff tends to not look consistent depending on view angle)));
_Color = lerp(fixed4(1,1,1,1), _Color, mainTex.a);
o.Albedo = lerp(mainTex.rgb * _Color.rgb, _FoamColor.rgb, foamTerm);
o.Alpha = mainTex.a * _Color.a;
o.Alpha = lerp(o.Alpha, _FoamColor.a, foamTerm);
//o.Albedo = fixed4(0, 0, abs(sceneZ - partZ), 1);
//Rim
half3 rim = smoothstep(_RimMax, _RimMin, 1 - Pow4(1 - ndv)) * _RimColor.rgb * _RimColor.a;
o.Emission += rim.rgb;
}
ENDCG
}
//Fallback "Diffuse"
CustomEditor "TCP2_MaterialInspector_SG"
}