unity shader中高光反射光照模型之顶点光照

Shader "JK/SpecularVertexLevel" {
Properties {
_Color ("Color", Color) = (1,1,1,1)
_Specular("Specular", Color) = (1, 1, 1, 1)
_Gloss("Gloss", Range(8.0, 256)) = 20
}
SubShader{
Pass{
Tags { "LightMode"="ForwardBase" }
CGPROGRAM
#pragma vertex vert 
#pragma fragment frag
#include "Lighting.cginc"


fixed4 _Color;
fixed4 _Specular;
float _Gloss;


struct a2v{
float4 vertex :POSITION;
float3 normal:NORMAL;
};


struct v2f{
float4 pos:SV_POSITION;
float3 color:COLOR;
};


v2f vert(a2v v){
v2f o;
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;
fixed3 worldNormal = normalize(mul(v.normal, (float3x3)_World2Object));
fixed3 worldLightDir = normalize(_WorldSpaceLightPos0.xyz);
fixed halfLambert = dot(worldNormal, worldLightDir) * 0.5 + 0.5;
fixed3 diffuse = _LightColor0.rgb * _Color.rgb * halfLambert;//saturate(dot(worldNormal, worldLightDir));
fixed3 reflectDir = normalize(reflect(-worldLightDir, worldNormal));
fixed3 viewDir = normalize(_WorldSpaceCameraPos.xyz - mul(_Object2World, v.vertex).xyz);
fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(saturate(dot(reflectDir, viewDir)), _Gloss);
o.color = ambient + diffuse + specular;
return o;
}


fixed4 frag(v2f i):SV_Target{
return fixed4(i.color, 1.0);
}




ENDCG
}
} 
FallBack "Diffuse"
}