Unity3D Shader 半兰伯特光照模型

//效果预览

//Shader代码

Shader "Unlit/HalfLambert"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _Diffuse ("Diffuse Color", Color) = (,,,)
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            // make fog work
            #pragma multi_compile_fog

            #include "UnityCG.cginc"
            #include "Lighting.cginc"

            struct a2v
            {
                float4 vertex : POSITION;
                float3 normal : NORMAL;
                float4 texcoord : TEXCOORD0;
            };  

            struct v2f
            {
                float2 uv : TEXCOORD0;
                UNITY_FOG_COORDS()
                float4 vertex : SV_POSITION;
                fixed3 worldNormal:TEXCOORD1;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;
            fixed4 _Diffuse;

            v2f vert (a2v v)
            {
                v2f o;
                o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
                o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
                o.worldNormal = mul((float3x3)unity_ObjectToWorld,v.normal);
                UNITY_TRANSFER_FOG(o,o.vertex);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                fixed3 worldLightDir = normalize(_WorldSpaceLightPos0.xyz);
                fixed3 worldNormal = normalize(i.worldNormal);

                fixed3 halLambert = 0.5+0.5*dot(worldLightDir,worldNormal);

                fixed3 dif = (UNITY_LIGHTMODEL_AMBIENT+halLambert*_LightColor0)*_Diffuse;

                // sample the texture
                fixed4 col = tex2D(_MainTex, i.uv);

                // apply fog
                UNITY_APPLY_FOG(i.fogCoord, col);
                return fixed4(dif * col.rgb, col.a); 

                return col;
            }
            ENDCG
        }
    }
}