Unity 通用透明物体漫反射Shader(双面渲染&多光源&光照衰减&法线贴图&凹凸透明度控制)
Shader "MyUnlit/AlphaBlendDiffuse" { Properties { _Color("Color Tint(贴图染色)",Color)=(1,1,1,1) _MainTex ("Texture(主贴图)", 2D) = "white" {} //bump为unity内置的法线纹理,当未配置任何法线纹理时,bump对应模型自带的法线信息 _NormalMap("Normal Map(法线贴图)",2D)="bump"{} _BumpScale("Bump Scale(凹凸程度)",float) = 1.0 _Cutoff("Alpha(整体透明度)",range(0,1)) = 0.5 } SubShader { //透明度混合需要定义的标签 Tags{ "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" } //1.Base Pass背面(顺序,透明物体先渲染背面再渲染正面) Pass { //提示此Pass为前向渲染中的Base Pass,计算环境光,自发光,平行光中的阴影,不计算其他叠加光照效果 Tags{ "LightMode" = "ForwardBase" } //透明度混合需要关闭深度写入 ZWrite Off //开启混合操作并设置混合类型,此处类型为透明度混合 Blend SrcAlpha OneMinusSrcAlpha //透明物体要考虑双面渲染,第一个Pass只渲染背面,剔除正面 Cull Front CGPROGRAM #pragma vertex vert #pragma fragment frag //Base Pass指令,用于得到对应的光照变量 #pragma multi_compile_fwdbase #include "UnityCG.cginc" //包含接收阴影的宏 #include "AutoLight.cginc" #include "Lighting.cginc" fixed4 _Color; sampler2D _MainTex; //用于控制对应纹理的缩放和偏移,格式固定为xx_ST float4 _MainTex_ST; sampler2D _NormalMap; float4 _NormalMap_ST; float _BumpScale; fixed _Cutoff;//[0,1]范围内用fixed struct appdata { float4 vertex : POSITION; float3 normal:NORMAL; float4 tangent:TANGENT;//与法线不同,w需要用于控制朝向 float2 uv : TEXCOORD0; }; struct v2f { //节约空间,xy分量存主贴图uv;zw存法线贴图的 float4 uv : TEXCOORD0; float4 pos : SV_POSITION;//变量名为pos,有关阴影计算的宏中使用了此变量 //寄存器中没法存矩阵,所以分别存矩阵的每一行 float4 TtoW0 : TEXCOORD1; float4 TtoW1 : TEXCOORD2; float4 TtoW2 : TEXCOORD3; SHADOW_COORDS(4)//此阴影纹理坐标存储在TEXCOORD4中 }; //此处采用在世界空间中计算法线 v2f vert (appdata v) { v2f o; o.pos = UnityObjectToClipPos(v.vertex); //用两个分量分别存储贴图的缩放和偏移 o.uv.xy = TRANSFORM_TEX(v.uv, _MainTex); o.uv.zw = TRANSFORM_TEX(v.uv, _NormalMap); float3 worldPos= mul(unity_ObjectToWorld, v.vertex).xyz; fixed3 worldNormal = UnityObjectToWorldNormal(v.normal); fixed3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz); //叉积计算第三个标准正交基轴向,w指示朝向的正负 fixed3 worldBinormal = cross(worldNormal, worldTangent) * v.tangent.w; //节约空间,顺便将世界空间中的顶点位置存在w分量中 o.TtoW0 = float4(worldTangent.x, worldBinormal.x, worldNormal.x, worldPos.x); o.TtoW1 = float4(worldTangent.y, worldBinormal.y, worldNormal.y, worldPos.y); o.TtoW2 = float4(worldTangent.z, worldBinormal.z, worldNormal.z, worldPos.z); //计算阴影纹理坐标 TRANSFER_SHADOW(o); return o; } fixed4 frag (v2f i) : SV_Target { //还原世界坐标 float3 worldPos = float3(i.TtoW0.w, i.TtoW1.w, i.TtoW2.w); //还原出矩阵,用于将纹理从顶点空间(切线空间)变为世界空间,统一计算 float3x3 TtoW= float3x3(i.TtoW0.xyz, i.TtoW1.xyz, i.TtoW2.xyz); //得到世界空间中的光源方向和视线方向 fixed3 lightDir = normalize(UnityWorldSpaceLightDir(worldPos)); fixed3 viewDir = normalize(UnityWorldSpaceViewDir(worldPos)); //从zw分量中采样出法线并进行凹凸程度的缩放,但此时法线依然处于顶点空间(切线空间) fixed3 tanNormal = UnpackNormalWithScale(tex2D(_NormalMap, i.uv.zw), _BumpScale); //通过之前构造的变换矩阵将法线从顶点空间变换到世界空间 fixed3 worldNormal = mul(TtoW, tanNormal); //采样主纹理并染色,得到反射率 fixed4 col = tex2D(_MainTex, i.uv); fixed3 albedo = col.rgb*_Color.rgb; //计算环境光 fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo; //计算漫反射 fixed3 diffuse = _LightColor0.rgb*albedo*saturate(dot(lightDir, worldNormal)); //计算光照和阴影衰减值,结果为第一个参数 UNITY_LIGHT_ATTENUATION(atten, i, worldPos); //返回计算结果 return fixed4(ambient + diffuse * atten, col.a * _Cutoff); } ENDCG } //2.Base Pass正面 Pass { Tags{ "LightMode" = "ForwardBase" } ZWrite Off Blend SrcAlpha OneMinusSrcAlpha //透明物体要考虑双面渲染,此Pass只渲染正面,剔除背面 Cull Back CGPROGRAM #pragma vertex vert #pragma fragment frag #pragma multi_compile_fwdbase #include "UnityCG.cginc" #include "AutoLight.cginc" #include "Lighting.cginc" fixed4 _Color; sampler2D _MainTex; float4 _MainTex_ST; sampler2D _NormalMap; float4 _NormalMap_ST; float _BumpScale; fixed _Cutoff; struct appdata { float4 vertex : POSITION; float3 normal:NORMAL; float4 tangent:TANGENT; float2 uv : TEXCOORD0; }; struct v2f { float4 uv : TEXCOORD0; float4 pos : SV_POSITION; float4 TtoW0 : TEXCOORD1; float4 TtoW1 : TEXCOORD2; float4 TtoW2 : TEXCOORD3; SHADOW_COORDS(4) }; v2f vert(appdata v) { v2f o; o.pos = UnityObjectToClipPos(v.vertex); o.uv.xy = TRANSFORM_TEX(v.uv, _MainTex); o.uv.zw = TRANSFORM_TEX(v.uv, _NormalMap); float3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz; fixed3 worldNormal = UnityObjectToWorldNormal(v.normal); fixed3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz); fixed3 worldBinormal = cross(worldNormal, worldTangent) * v.tangent.w; o.TtoW0 = float4(worldTangent.x, worldBinormal.x, worldNormal.x, worldPos.x); o.TtoW1 = float4(worldTangent.y, worldBinormal.y, worldNormal.y, worldPos.y); o.TtoW2 = float4(worldTangent.z, worldBinormal.z, worldNormal.z, worldPos.z); TRANSFER_SHADOW(o); return o; } fixed4 frag(v2f i) : SV_Target { float3 worldPos = float3(i.TtoW0.w, i.TtoW1.w, i.TtoW2.w); float3x3 TtoW = float3x3(i.TtoW0.xyz, i.TtoW1.xyz, i.TtoW2.xyz); fixed3 lightDir = normalize(UnityWorldSpaceLightDir(worldPos)); fixed3 viewDir = normalize(UnityWorldSpaceViewDir(worldPos)); fixed3 tanNormal = UnpackNormalWithScale(tex2D(_NormalMap, i.uv.zw), _BumpScale); fixed3 worldNormal = mul(TtoW, tanNormal); fixed4 col = tex2D(_MainTex, i.uv); fixed3 albedo = col.rgb*_Color.rgb; fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo; fixed3 diffuse = _LightColor0.rgb*albedo*saturate(dot(lightDir, worldNormal)); UNITY_LIGHT_ATTENUATION(atten, i, worldPos); return fixed4(ambient + diffuse * atten, col.a * _Cutoff); } ENDCG } //3.Add Pass正常渲染 Pass { //提示此Pass为前向渲染中的Add Pass,计算其他叠加光照效果,每个光源计算一次 Tags{ "LightMode" = "ForwardAdd" } ZWrite Off Blend SrcAlpha One Cull Back CGPROGRAM #pragma vertex vert #pragma fragment frag //Add Pass指令,用于得到对应的光照变量 //#pragma multi_compile_fwdadd //阴影情况下使用: #pragma multi_compile_fwdadd_fullshadows #include "UnityCG.cginc" #include "AutoLight.cginc" #include "Lighting.cginc" fixed4 _Color; sampler2D _MainTex; float4 _MainTex_ST; sampler2D _NormalMap; float4 _NormalMap_ST; float _BumpScale; fixed _Cutoff; struct appdata { float4 vertex : POSITION; float3 normal:NORMAL; float4 tangent:TANGENT; float2 uv : TEXCOORD0; }; struct v2f { float4 uv : TEXCOORD0; float4 pos : SV_POSITION; float4 TtoW0 : TEXCOORD1; float4 TtoW1 : TEXCOORD2; float4 TtoW2 : TEXCOORD3; SHADOW_COORDS(4) }; v2f vert(appdata v) { v2f o; o.pos = UnityObjectToClipPos(v.vertex); o.uv.xy = TRANSFORM_TEX(v.uv, _MainTex); o.uv.zw = TRANSFORM_TEX(v.uv, _NormalMap); float3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz; fixed3 worldNormal = UnityObjectToWorldNormal(v.normal); fixed3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz); fixed3 worldBinormal = cross(worldNormal, worldTangent) * v.tangent.w; o.TtoW0 = float4(worldTangent.x, worldBinormal.x, worldNormal.x, worldPos.x); o.TtoW1 = float4(worldTangent.y, worldBinormal.y, worldNormal.y, worldPos.y); o.TtoW2 = float4(worldTangent.z, worldBinormal.z, worldNormal.z, worldPos.z); TRANSFER_SHADOW(o); return o; } fixed4 frag(v2f i) : SV_Target { float3 worldPos = float3(i.TtoW0.w, i.TtoW1.w, i.TtoW2.w); float3x3 TtoW = float3x3(i.TtoW0.xyz, i.TtoW1.xyz, i.TtoW2.xyz); fixed3 lightDir = normalize(UnityWorldSpaceLightDir(worldPos)); fixed3 viewDir = normalize(UnityWorldSpaceViewDir(worldPos)); fixed3 tanNormal = UnpackNormalWithScale(tex2D(_NormalMap, i.uv.zw), _BumpScale); fixed3 worldNormal = mul(TtoW, tanNormal); fixed4 col = tex2D(_MainTex, i.uv); fixed3 albedo = col.rgb*_Color.rgb; fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo; fixed3 diffuse = _LightColor0.rgb*albedo*saturate(dot(lightDir, worldNormal)); UNITY_LIGHT_ATTENUATION(atten, i, worldPos); return fixed4(ambient + diffuse * atten, col.a * _Cutoff); } ENDCG } } //无阴影 //FallBack "Transparent/VertexLit" //强制产生阴影 FallBack "VertexLit" }
对于至今为止Shader学习内容的一个总结,算是一个比较综合通用的shader了,因为是漫反射所以暂时没有计算高光部分,之后再出一个带高光版本的。
备注都有比较详细的说明,基本思路是利用多个Pass分别进行正反面的渲染,再结合前向渲染的分光照渲染来实现。
最后摆出效果图w~
最新评论