Unity shader学习之标准的Unity shader

包含光照，可处理多个光源，有光照衰减和阴影的shader，代码如下：

转载请注明出处：http://www.cnblogs.com/jietian331/p/7199311.html

Shader "Custom/Bumped Specular"
{
    Properties
    {
        _MainTex("Main Texture", 2D) = "white" {}
        _NormalMap("Normal Map", 2D) = "bump" {}
        _Specular("Specular", Color) = (1,1,1,1)
        _Gloss("Gloss", Range(8, 256)) = 8
    }

    SubShader
    {
        Tags
        {
            "Queue" = "Geometry"
            "RenderType" = "Opaque"
        }

        Pass
        {
            Tags
            {
                "LightMode" = "ForwardBase"
            }
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma multi_compile_fwdbase

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

            sampler2D _MainTex;
            float4 _MainTex_ST;
            sampler2D _NormalMap;
            float4 _NormalMap_ST;
            fixed4 _Specular;
            float _Gloss;

            struct appdata
            {
                float4 vertex : POSITION;
                float4 uv : TEXCOORD0;
                fixed4 color : COLOR;
                float4 tangent : TANGENT;
                float3 normal : NORMAL;
            };

            struct v2f
            {
                float4 pos : SV_POSITION;
                float4 uv : TEXCOORD0;
                fixed4 color : COLOR;
                float4 T2W1 : TEXCOORD1;
                float4 T2W2 : TEXCOORD2;
                float4 T2W3 : TEXCOORD3;
                SHADOW_COORDS(4)
            };

            v2f vert(appdata v)
            {
                v2f o;
                o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
                float2 uv1 = v.uv.xy * _MainTex_ST.xy + _MainTex_ST.zw;
                float2 uv2 = v.uv.zw * _NormalMap_ST.xy + _NormalMap_ST.zw;
                o.uv = float4(uv1, uv2);
                o.color = v.color;

                float3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz);
                float3 worldNormal = UnityObjectToWorldNormal(v.normal);
                float3 binormal = cross(normalize(worldNormal), normalize(worldTangent)) * v.tangent.w;
                float3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
                o.T2W1 = float4(worldTangent.x, binormal.x, worldNormal.x, worldPos.x);
                o.T2W2 = float4(worldTangent.y, binormal.y, worldNormal.y, worldPos.y);
                o.T2W3 = float4(worldTangent.z, binormal.z, worldNormal.z, worldPos.z);
                TRANSFER_SHADOW(o);
                return o;
            }

            fixed4 frag(v2f i) : SV_TARGET
            {
                float3 worldPos = float3(i.T2W1.w, i.T2W2.w, i.T2W3.w);
                float3 worldLight = normalize(UnityWorldSpaceLightDir(worldPos));
                float3 worldView = normalize(UnityWorldSpaceViewDir(worldPos));

                fixed4 albedo = tex2D(_MainTex, i.uv.xy) * i.color;
                float3 tangentNormal = UnpackNormal(tex2D(_NormalMap, i.uv.zw));
                float3x3 tanToWorld = float3x3(i.T2W1.xyz, i.T2W2.xyz, i.T2W3.xyz);
                float3 worldNormal = mul(tanToWorld, tangentNormal);

                fixed3 ambient = albedo.xyz * UNITY_LIGHTMODEL_AMBIENT.xyz;

                fixed3 diffuse = albedo.xyz * _LightColor0.xyz * max(0, dot(worldLight, worldNormal));

                float3 halfDir = normalize(worldLight + worldView);
                fixed3 specular = albedo.xyz * _Specular * pow(max(0, dot(worldNormal, halfDir)), _Gloss);

                UNITY_LIGHT_ATTENUATION(atten, i, worldPos);

                fixed3 col = ambient + (diffuse + specular) * atten;
                return fixed4(col, 1);
            }

            ENDCG
        }

        Pass
        {
            Tags
            {
                "LightMode" = "ForwardAdd"
            }
            Blend One One

            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma multi_compile_fwdadd_fullshadows

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

            sampler2D _MainTex;
            float4 _MainTex_ST;
            sampler2D _NormalMap;
            float4 _NormalMap_ST;
            fixed4 _Specular;
            float _Gloss;

            struct appdata
            {
                float4 vertex : POSITION;
                float4 uv : TEXCOORD0;
                fixed4 color : COLOR;
                float4 tangent : TANGENT;
                float3 normal : NORMAL;
            };

            struct v2f
            {
                float4 pos : SV_POSITION;
                float4 uv : TEXCOORD0;
                fixed4 color : COLOR;
                float4 T2W1 : TEXCOORD1;
                float4 T2W2 : TEXCOORD2;
                float4 T2W3 : TEXCOORD3;
                SHADOW_COORDS(4)
            };

            v2f vert(appdata v)
            {
                v2f o;
                o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
                float2 uv1 = v.uv.xy * _MainTex_ST.xy + _MainTex_ST.zw;
                float2 uv2 = v.uv.zw * _NormalMap_ST.xy + _NormalMap_ST.zw;
                o.uv = float4(uv1, uv2);
                o.color = v.color;

                float3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz);
                float3 worldNormal = UnityObjectToWorldNormal(v.normal);
                float3 binormal = cross(normalize(worldNormal), normalize(worldTangent)) * v.tangent.w;
                float3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
                o.T2W1 = float4(worldTangent.x, binormal.x, worldNormal.x, worldPos.x);
                o.T2W2 = float4(worldTangent.y, binormal.y, worldNormal.y, worldPos.y);
                o.T2W3 = float4(worldTangent.z, binormal.z, worldNormal.z, worldPos.z);
                TRANSFER_SHADOW(o);
                return o;
            }

            fixed4 frag(v2f i) : SV_TARGET
            {
                float3 worldPos = float3(i.T2W1.w, i.T2W2.w, i.T2W3.w);
                float3 worldLight = normalize(UnityWorldSpaceLightDir(worldPos));
                float3 worldView = normalize(UnityWorldSpaceViewDir(worldPos));

                fixed4 albedo = tex2D(_MainTex, i.uv.xy) * i.color;
                float3 tangentNormal = UnpackNormal(tex2D(_NormalMap, i.uv.zw));
                float3x3 tanToWorld = float3x3(i.T2W1.xyz, i.T2W2.xyz, i.T2W3.xyz);
                float3 worldNormal = mul(tanToWorld, tangentNormal);

                fixed3 diffuse = albedo.xyz * _LightColor0.xyz * max(0, dot(worldLight, worldNormal));

                float3 halfDir = normalize(worldLight + worldView);
                fixed3 specular = albedo.xyz * _Specular * pow(max(0, dot(worldNormal, halfDir)), _Gloss);

                UNITY_LIGHT_ATTENUATION(atten, i, worldPos);

                fixed3 col = (diffuse + specular) * atten;
                return fixed4(col, 1);
            }

            ENDCG
        }
    }

    Fallback "Specular"
}

效果如下：