Shader-基础光照-高光反射光照模型

Shader "Unlit/SingleTexture"
{
    Properties{
        _Color("Color Tint",Color) = (1,1,1,1)
        _MainTex("Main Tex",2D) = "white"{}
        _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;
                sampler2D _MainTex;
                float4 _MainTex_ST;
                fixed4 _Specular;
                float _Gloss;

                struct  a2v{
                    float4 vertex : POSITION;
                    float3 normal : NORMAL;
                    float4 texcoord : TEXCOORD0;
                };
                struct v2f {
                    float4 pos : SV_POSITION;
                    float3 worldNormal : TEXCOORD0;
                    float3 worldPos : TEXCOORD1;
                    float2 uv : TEXCOORD2;
                };
                v2f vert(a2v v) {
                    v2f o;
                    //o.pos = UnityObjectToClipPos(v.vertex);
                    o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
                    o.worldNormal= UnityObjectToWorldNormal(v.normal);
                    o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
                    o.uv = v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw;
                    return o;
                }
                fixed4 frag(v2f i) : SV_Target{
                    fixed3 worldNormal = normalize(i.worldNormal);                  
                    fixed3 worldLightDir = normalize(UnityWorldSpaceLightDir(i.worldPos));
                    fixed3 albedo = tex2D(_MainTex, i.uv).rgb * _Color.rgb;
                    fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz  * albedo;
                    fixed3 diffuse = _LightColor0.rgb * albedo * max(0, dot(worldNormal, worldLightDir));
                    fixed3 viewDir = normalize(UnityWorldSpaceViewDir(i.worldPos));
                    fixed3 halfDir = normalize(worldLightDir + viewDir);
                    fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(0, dot(worldNormal, halfDir)), _Gloss);

                    return fixed4(ambient + diffuse + specular,1.0);
                }
                ENDCG
            }
        }
        Fallback "Specular"
}