UnitySahder实现Phong/BlinnPhong模型-编程知识

UnitySahder实现Phong/BlinnPhong模型

Phong模型公式：

BlinnPhong模型公式：

实现：

Phong模型：

BlinnPhong模型：

Phong模型公式：

结果=自发光＋环境光+漫反射+高光反射

BlinnPhong模型公式：

对Phong模型的简单修改，修改部分在于高光反射部分，其公式为：

$c_{specular}=\left ( c_{light}\cdot m_{specular} \right )max\left ( 0,\widehat{n}\cdot \widehat{h} \right )^{m_{gloss}}$

其中n为表面法线，h为视角方向和光照方向相加后归一化所得，也叫做半角方向。

实现：

Phong模型：

Shader "MyShader/Phong"
{Properties{_DiffuseColor("漫反射颜色",color)=(1,1,1,1)_SpecularColor("高光颜色",color)=(1,1,1,1)_Gloss("高光范围",Range(0,256))=30[Toggle]_halfLambert("开启半兰伯特",int)=0}SubShader{Pass{Tags{"LightMode"="ForwardBase"}CGPROGRAM#pragma vertex vert #pragma fragment frag #include "UnityCg.cginc"#include "Lighting.cginc"float _Gloss;float4 _SpecularColor;float4  _DiffuseColor;bool _halfLambert;struct vertexInput {float4 vertex:POSITION;float3 normal:NORMAL;};struct vertexOutput{float4 pos:SV_POSITION;fixed3 worldNormal:TEXCOORD0;float3 worldPos:TEXCOORD2;};vertexOutput vert(vertexInput v){vertexOutput o=(vertexOutput)0;o.pos=UnityObjectToClipPos(v.vertex);o.worldNormal=UnityObjectToWorldNormal(v.normal);o.worldPos=mul(unity_ObjectToWorld,v.vertex).xyz;return o;}float4 frag(vertexOutput i):SV_TARGET{fixed3 worldNormal=normalize(i.worldNormal);fixed3 worldLightDir=normalize(_WorldSpaceLightPos0.xyz);float lambert=saturate(dot(worldLightDir,worldNormal));float halflambert=dot(worldLightDir,worldNormal)*0.5+0.5;fixed3 viewDir=normalize(_WorldSpaceCameraPos.xyz-i.worldPos);fixed3 reflectDir=normalize(reflect(-worldLightDir,worldNormal));fixed3 ambient=UNITY_LIGHTMODEL_AMBIENT.xyz;fixed3 diffuseTemp=_DiffuseColor.rgb*_LightColor0.rgb;fixed3 specular=_SpecularColor.rgb*_LightColor0.rgb*pow(saturate(dot(viewDir,reflectDir)),_Gloss);if(_halfLambert)return float4(diffuseTemp*halflambert+specular+ambient,1.0);elsereturn float4(diffuseTemp*lambert+specular+ambient,1.0);}ENDCG}}
}

BlinnPhong模型：

Shader "MyShader/BlinnPhong"
{Properties{_DiffuseColor("漫反射颜色",color)=(1,1,1,1)_SpecluarColor("高光反射颜色",color)=(1,1,1,1)_Gloss("高光反射范围",Range(0,256))=30[Toggle]_halfLambert("开启半兰伯特",float)=0}SubShader{Pass{Tags{"LightMode"="ForwardBase"}CGPROGRAM#pragma vertex vert #pragma fragment frag#include "UnityCG.cginc"#include "Lighting.cginc"fixed4 _DiffuseColor;fixed4 _SpecluarColor;float _Gloss;bool _halfLambert;struct vertexInput{float4 vertex:POSITION;fixed3 normal:NORMAL;};struct vertexOutput{float4 pos:SV_POSITION;fixed3 worldNormal:TEXCOORD0;fixed3 worldPos:TEXCOORD1;};vertexOutput vert(vertexInput v){vertexOutput o=(vertexOutput)0;o.pos=UnityObjectToClipPos(v.vertex);o.worldNormal=UnityObjectToWorldNormal(v.normal);o.worldPos=mul(unity_ObjectToWorld,v.vertex).xyz;return o;}float4 frag(vertexOutput i):SV_TARGET{fixed3 worldNormal = normalize(i.worldNormal);fixed3 worldLightDir = normalize(_WorldSpaceLightPos0.xyz);fixed3 viewDir = normalize(_WorldSpaceCameraPos.xyz-i.worldPos.xyz);fixed3 hDir=normalize(worldLightDir+viewDir);float lambert=saturate(dot(worldLightDir,worldNormal));float halflambert=dot(worldLightDir,worldNormal)*0.5+0.5;fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT;fixed3 specular = _SpecluarColor.rgb*_LightColor0.rgb*pow(saturate(dot(worldNormal,hDir)),_Gloss);fixed3 diffuseTemp = _DiffuseColor.rgb*_LightColor0.rgb;if(_halfLambert)return float4(diffuseTemp*halflambert+ambient+specular,1.0);elsereturn float4(diffuseTemp*lambert+ambient+specular,1.0);}ENDCG}}
}

效果：