Unityshader实例02:Xray材质

实现效果

需要实现的效果大概如下图所示

原理及思路

由图大概可知道X射线效果是中间很透明边缘比较亮的渐变效果，因此实现这种效果的话需要使用边缘光效果。

正常来说，物体法线与视线(从顶点至相机的方向)角度越一致，就越是能被玩家看见的中间。而边缘一般与法线垂直。由点乘即可计算轮廓光。
half rim = 1.0 - saturate(dot (normalize(IN.viewDir), o.Normal));

shader代码实现

VF版本代码01:

Shader "PengLu/XRaySimpleVF" {Properties {_RimColor("RimColor",Color) = (1,1,0,1)_RimPower ("Rim Power", Range(0.1,8.0)) = 3.0}SubShader {Tags { "Queue"="Transparent" "RenderType"="Opaque" }LOD 200Pass{Blend SrcAlpha OneZWrite offLighting offCGPROGRAM#pragma vertex vert#pragma fragment frag#include "UnityCG.cginc"float4 _RimColor;float _RimPower;struct appdata_t {float4 vertex : POSITION;float2 texcoord : TEXCOORD0;float4 color:COLOR;float4 normal:NORMAL;};struct v2f {float4  pos : SV_POSITION;float4color:COLOR;} ;v2f vert (appdata_t v){v2f o;o.pos = mul(UNITY_MATRIX_MVP,v.vertex);float3 viewDir = normalize(ObjSpaceViewDir(v.vertex));                float rim = 1 - saturate(dot(viewDir,v.normal ));               o.color = _RimColor*pow(rim,_RimPower);return o;}float4 frag (v2f i) : COLOR{return i.color; }ENDCG}} FallBack "Diffuse"}

VF版本代码01效果：

VF版本代码02:法线贴图

Shader "PengLu/XRayBumpVF"{Properties {_BumpMap ("Normalmap", 2D) = "bump" {}_RimColor("RimColor",Color) = (1,1,0,1)_RimPower ("Rim Power", Range(0.1,8)) = 3.0}SubShader {Tags { "Queue"="Transparent" "RenderType"="Opaque" }LOD 200Pass{Blend SrcAlpha OneZWrite offLighting offCGPROGRAM#pragma vertex vert#pragma fragment frag#include "UnityCG.cginc"float4 _RimColor;sampler2D _BumpMap;float _RimPower;float4 _BumpMap_ST;struct v2f {float4  pos : SV_POSITION;float2 uv : TEXCOORD0;float3 viewDir:TEXCOORD1;float3 tangent:TEXCOORD2;float3 binormal:TEXCOORD3;float3 normal:TEXCOORD4;} ;v2f vert (appdata_full v){v2f o;o.pos = mul(UNITY_MATRIX_MVP,v.vertex);o.uv = TRANSFORM_TEX( v.texcoord, _BumpMap );o.tangent=v.tangent.xyz;o.binormal=cross(v.normal,v.tangent)*v.tangent.w;o.normal=v.normal;o.viewDir = normalize(ObjSpaceViewDir(v.vertex));return o;}float4 frag (v2f i) : COLOR{float3x3 rotation=float3x3 (i.tangent.xyz,i.binormal,i.normal);//float4 packedN=tex2D(_BumpMap,i.uv);//float3 N=float3(2.0*packedN.wy-1,1.0);//N.z=sqrt(1-N.x*N.x-N.y*N.y);float3 N = UnpackNormal(tex2D(_BumpMap,i.uv));N=normalize(mul(N,rotation));//把从贴图中得到的法线转换到世界坐标中float rim=1 - saturate(dot(i.viewDir,N));float4 c=_RimColor*pow(rim,_RimPower);return c; }ENDCG}} FallBack "Diffuse"}

VF版本代码02效果：

PS：fragment中使用了Unity定义在UnityCG.cginc中的函数UnpackNormal，下面是这个函数的原型，多了对移动平台RGB法线贴图的支持

inline fixed3 UnpackNormal(fixed4 packednormal){#if defined (SHADER_API_GLES) && defined(SHADER_API_MOBILE)return packednormal.xyz*2-1;#elsefixed3 normal;normal.xy=packednormal.wy*2-1;normal.z = sqrt(1-normal.x*normal.x-normal.y*normal.y);return normal;#endif}

Surf版本代码03:

Shader "PengLu/XRaySimpleSurf"{Properties {_RimColor("RimColor",Color) = (1,1,0,1)_RimPower ("Rim Power", Range(0.1,8)) = 3.0}SubShader {Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}LOD 200CGPROGRAM#pragma surface surf Lambert  alpha:blend#include "UnityCG.cginc"float4 _RimColor;float _RimPower;struct Input {float3 viewDir;};void surf (Input IN, inout SurfaceOutput o) {                     half rim = 1.0 - saturate(dot (normalize(IN.viewDir), o.Normal));        float4 c=_RimColor * pow (rim, _RimPower);         o.Alpha=c.a;                         o.Emission =c.rgb*2;  }ENDCG} FallBack "PengLu/XRaySimpleVF"}

Surf版本代码03效果：

Surf版本代码04:法线贴图

Shader "PengLu/XRayBumpSurf"{Properties {_BumpMap ("Normalmap", 2D) = "bump" {}_RimColor("RimColor",Color) = (1,1,0,1)_RimPower ("Rim Power", Range(0.1,8)) = 3.0}SubShader {Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}LOD 200CGPROGRAM#pragma surface surf Lambert  alpha:blendfloat4 _RimColor;float _RimPower;sampler2D _BumpMap;struct Input {float2 uv_BumpMap;float3 viewDir;};void surf (Input IN, inout SurfaceOutput o) {o.Normal = UnpackNormal(tex2D(_BumpMap, IN.uv_BumpMap));                     half rim = 1.0 - saturate(dot (normalize(IN.viewDir), o.Normal));        float4 c=_RimColor * pow (rim, _RimPower);         o.Alpha=c.a;                         o.Emission =c.rgb*2;  }ENDCG} FallBack "PengLu/XRaySimpleSurf"}

Surf版本代码04效果：

MatCap版本

关于MatCap原理解释可以参考这里和这里，利用一张正方形的贴图存储灯光信息，因此在这里也可以利用来制作XRay效果，前提需要用到一张类似下面这样的的贴图：

MatCap版本VF代码05

Shader "PengLu/XrayMatCapSimpleVF"{Properties{_Color ("Main Color", Color) = (0.5,0.5,0.5,1)_MatCap ("MatCap (RGB)", 2D) = "white" {}}Subshader{Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent" }Blend SrcAlpha OneCull OffLighting OffZWrite OffPass{Tags { "LightMode" = "Always" }CGPROGRAM#pragma vertex vert#pragma fragment frag#pragma fragmentoption ARB_precision_hint_fastest#include "UnityCG.cginc"struct v2f{float4 pos: SV_POSITION;float2 cap: TEXCOORD0;};v2f vert (appdata_base v){v2f o;o.pos = mul (UNITY_MATRIX_MVP, v.vertex);float3 worldNorm = normalize(_World2Object[0].xyz * v.normal.x + _World2Object[1].xyz * v.normal.y + _World2Object[2].xyz * v.normal.z);worldNorm = mul((float3x3)UNITY_MATRIX_V, worldNorm);o.cap.xy = worldNorm.xy * 0.5 + 0.5;return o;}uniform float4 _Color;uniform sampler2D _MatCap;float4 frag (v2f i) : COLOR{float4 mc = tex2D(_MatCap, i.cap);return _Color * mc * 1.0;}ENDCG}}Fallback "VertexLit"}

MatCap版本VF代码05效果

MatCap版本VF代码06:法线贴图

Shader "PengLu/XrayMatCapBumpVF"{Properties{_Color ("Main Color", Color) = (0.5,0.5,0.5,1)_BumpMap ("Normal Map", 2D) = "bump" {}_MatCap ("MatCap (RGB)", 2D) = "white" {}[Toggle(MATCAP_ACCURATE)] _MatCapAccurate ("Accurate Calculation", Int) = 0}Subshader{Tags { "RenderType"="Opaque" }blend one oneZwrite offPass{Tags { "LightMode" = "Always" }CGPROGRAM#pragma vertex vert#pragma fragment frag#pragma fragmentoption ARB_precision_hint_fastest#pragma shader_feature MATCAP_ACCURATE#include "UnityCG.cginc"struct v2f{float4 pos: SV_POSITION;float2 uv_bump : TEXCOORD0;#if MATCAP_ACCURATEfixed3 tSpace0 : TEXCOORD1;fixed3 tSpace1 : TEXCOORD2;fixed3 tSpace2 : TEXCOORD3;#elsefloat3 c0 : TEXCOORD1;float3 c1 : TEXCOORD2;#endif};uniform float4 _BumpMap_ST;v2f vert (appdata_tan v){v2f o;o.pos = mul (UNITY_MATRIX_MVP, v.vertex);o.uv_bump = TRANSFORM_TEX(v.texcoord,_BumpMap);#if MATCAP_ACCURATE//Accurate bump calculation: calculate tangent space matrix and pass it to fragment shaderfixed3 worldNormal = UnityObjectToWorldNormal(v.normal);fixed3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz);fixed3 worldBinormal = cross(worldNormal, worldTangent) * v.tangent.w;o.tSpace0 = fixed3(worldTangent.x, worldBinormal.x, worldNormal.x);o.tSpace1 = fixed3(worldTangent.y, worldBinormal.y, worldNormal.y);o.tSpace2 = fixed3(worldTangent.z, worldBinormal.z, worldNormal.z);#else//Faster but less accurate method (especially on non-uniform scaling)v.normal = normalize(v.normal);TANGENT_SPACE_ROTATION;o.c0 = mul(rotation, normalize(UNITY_MATRIX_IT_MV[0].xyz));o.c1 = mul(rotation, normalize(UNITY_MATRIX_IT_MV[1].xyz));#endifreturn o;}uniform float4 _Color;uniform sampler2D _MatCap;uniform sampler2D _BumpMap;float4 frag (v2f i) : COLOR{fixed3 normals = UnpackNormal(tex2D(_BumpMap, i.uv_bump));#if MATCAP_ACCURATE//Rotate normals from tangent space to world spacefloat3 worldNorm;worldNorm.x = dot(i.tSpace0.xyz, normals);worldNorm.y = dot(i.tSpace1.xyz, normals);worldNorm.z = dot(i.tSpace2.xyz, normals);worldNorm = mul((float3x3)UNITY_MATRIX_V, worldNorm);float4 mc = tex2D(_MatCap, worldNorm.xy * 0.5 + 0.5);#elsehalf2 capCoord = half2(dot(i.c0, normals), dot(i.c1, normals));float4 mc = tex2D(_MatCap, capCoord*0.5+0.5);#endifreturn _Color * mc * 2.0;}ENDCG}}Fallback "VertexLit"}

MatCap版本VF代码06效果：

MatCap版本Surf代码07:法线贴图

Shader "PengLu/XrayMatCapBumpSurf" {Properties {_MainTint ("Diffuse Tint", Color) = (1,1,1,1)_MatCap ("MatCap (RGB", 2D) = "white" {}_NormalMap ("Normal Map", 2D) = "bump" {}}SubShader {Tags { "RenderType"="Opaque" }LOD 200Blend one oneCGPROGRAM#pragma surface surf Unlit vertex:vert#pragma target 3.0float4 _MainTint;sampler2D _MatCap;sampler2D _NormalMap;inline half4 LightingUnlit (SurfaceOutput s, fixed3 lightDir, fixed atten){half4 c = half4(1,1,1,1);c.rgb = s.Albedo;c.a = s.Alpha;return c;}struct Input {float2 uv_MatCap;float2 uv_NormalMap;float3 tan1;float3 tan2;};void vert (inout appdata_full v, out Input o)         {            UNITY_INITIALIZE_OUTPUT(Input,o);                      TANGENT_SPACE_ROTATION;//            o.tan1 = mul(rotation, UNITY_MATRIX_IT_MV[0].xyz);//            o.tan2 = mul(rotation, UNITY_MATRIX_IT_MV[1].xyz);            o.tan1 = mul(rotation, normalize(UNITY_MATRIX_IT_MV[0].xyz));o.tan2 = mul(rotation, normalize(UNITY_MATRIX_IT_MV[1].xyz));        }void surf (Input IN, inout SurfaceOutput o) {float3 normals = UnpackNormal(tex2D(_NormalMap, IN.uv_NormalMap));o.Normal = normals;float2 litSphereUV;litSphereUV.x = dot(IN.tan1, o.Normal);litSphereUV.y = dot(IN.tan2, o.Normal);half4 c = tex2D (_MatCap, litSphereUV*0.5+0.5);o.Albedo = c.rgb * _MainTint;o.Alpha = c.a;}ENDCG} FallBack "Diffuse"}

MatCap版本Surf代码07效果