Unity Shader：（八）高光反射光照模型

Shader "Unlit/Blinn-Phong"
{
    Properties
    {
        _Diffuse("漫反射颜色",Color) = (1,1,1,1)
        _Specular("高光反射颜色",Color) = (1,1,1,1)
        _Gloss("高光区域大小",Range(8.0,256)) = 20
    }
        SubShader
    {
        Pass
        {
            Tags { "LightMode" = "ForwardBase" }

            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "Lighting.cginc" //为了使用_LightColor0变量

            fixed4 _Diffuse;
            fixed4 _Specular;
            float _Gloss;

            struct a2f
            {
                float4 vertex:POSITION;
                float3 normal:NORMAL;
            };
            struct v2f
            {
                float4 pos : SV_POSITION;
                fixed3 worldNormal : TEXCOORD0;
                fixed3 worldPos : TEXCOORD1;
            };

            v2f vert(a2f v)
            {
                v2f o;
                o.pos = UnityObjectToClipPos(v.vertex);
                o.worldNormal = UnityObjectToWorldNormal(v.normal); //UnityCG.cginc帮助函数
                o.worldPos = mul(unity_ObjectToWorld,v.vertex).xyz;
                return o;
            }

            fixed4 frag(v2f i) : SV_Target
            {
                fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;
                fixed3 worldNormal = normalize(i.worldNormal);
                fixed3 worldLight = normalize(UnityWorldSpaceLightDir(i.worldPos));//UnityCG.cginc帮助函数
                fixed3 diffuse = _LightColor0.rgb * _Diffuse.rgb * saturate(dot(worldNormal, worldLight));
                fixed3 reflectDir = normalize(reflect(-worldLight, worldNormal));
                fixed3 viewDir = normalize(UnityWorldSpaceViewDir(i.worldPos)); //UnityCG.cginc帮助函数
                fixed3 halfDir = normalize(worldLight + viewDir);
                fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(0,dot(worldNormal,halfDir)), _Gloss);
                return fixed4(ambient + diffuse + specular,1.0);
            }
            ENDCG
        }
    }
    Fallback "Specular"
}

在材质面板的显示：

 在物体上的效果：