unity shader (7)

摘自冯乐乐的《unity shader 入门精要》

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Shader "Custom/SpecularPixelLevel" {

Properties

{

_Diffuse ("Diffuse" , Color)=(1, 1, 1, 1)

_Specular ("Specular", Color)=(1, 1, 1, 1)

_Gloss ("Gloss",Range(8.0 ,256.0))= 20

}

SubShader

{

Pass

{

Tags{"LightMode"="ForwardBase"}

CGPROGRAM

#pragma vertex vert

#pragma fragment frag

#include "Lighting.cginc"

fixed4 _Diffuse;

fixed4 _Specular;

float _Gloss;

struct a2v

{

float4 vertex : POSITION;

float4 normal : NORMAL;

};

struct v2f

{

float4 pos : SV_POSITION;

float3 worldNormal : TEXCOORD0;

float3 worldPos : TEXCOORD1;

};

v2f vert (a2v v)

{

v2f o;

// Transform the vertex from object space to projection space

//把局部顶点光照投射到空间

o.pos = mul(UNITY_MATRIX_MVP, v.vertex);

//Transform the normal from object space to world space;

//把局部法线转换到空间法线

o.worldNormal = mul(v.normal, (float3x3)_World2Object);

//Transform the vertex from obeject space to world space;

//把局部顶点光照转换到空间中

o.worldPos = mul(_Object2World , v.vertex).xyz;

return o;

}

fixed4 frag (v2f i) : SV_Target

{

//Get ambient term

fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;

fixed3 worldNormal = normalize (i.worldNormal);

fixed3 worldLightDir = normalize (_WorldSpaceLightPos0.xyz);

//Coumpute diffuse term

fixed3 diffuse = _LightColor0.rgb * _Diffuse .rgb * saturate(dot(worldNormal,worldLightDir));

//Get the reflect direction in world space;

//获取空间中的光照方向

fixed3 reflectDir = normalize (reflect (-worldLightDir,worldNormal));

//Get view direction in world space;

//获得视窗的光照方向

fixed3 viewDir = normalize(_WorldSpaceCameraPos.xyz - i.worldPos.xyz);

//Compute sepcular term

fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(saturate(dot(reflectDir,viewDir)),_Gloss);

return fixed4(ambient + diffuse + specular, 1.0);

}

ENDCG

}

FallBack "Specular"

}