今天要学习的是一些Shader 的例子,从简单到难。Let's go.
一大波例子来袭
还是用上一篇用到的工程。点我下载
Test1.shader
Shader "Custom/Test1" { SubShader { Tags { "RenderType" = "Opaque" } CGPROGRAM #pragma surface surf Lambert struct Input { float4 color : COLOR; }; void surf (Input IN, inout SurfaceOutput o) { o.Albedo = 1; } ENDCG } Fallback "Diffuse" }
带法线贴图的螃蟹
Shader "Custom/Test2" { Properties { _MainTex ("Texture", 2D) = "white" {} _BumpMap ("Bumpmap", 2D) = "bump" {} } SubShader { Tags { "RenderType" = "Opaque" } CGPROGRAM #pragma surface surf Lambert struct Input { float2 uv_MainTex; float2 uv_BumpMap; }; sampler2D _MainTex; sampler2D _BumpMap; void surf (Input IN, inout SurfaceOutput o) { o.Albedo = tex2D (_MainTex, IN.uv_MainTex).rgb; o.Normal = UnpackNormal (tex2D (_BumpMap, IN.uv_BumpMap)); } ENDCG } Fallback "Diffuse" }
对比感受一下,左边是不带法线贴图的,右边是带法线贴图的。
从剑灵里面跑出来的螃蟹
先看下啥是剑灵风
感觉就是很多高光有木有(不要瞎瞅,喂!),这还有个专业名词,叫Rim Lighting。我们的螃蟹也可以,哼~
Shader "Custom/Test3" { Properties { _MainTex ("Texture", 2D) = "white" {} _BumpMap ("Bumpmap", 2D) = "bump" {} _RimColor ("Rim Color", Color) = (0.26,0.19,0.16,0.0) _RimPower ("Rim Power", Range(0.5,8.0)) = 3.0 } SubShader { Tags { "RenderType" = "Opaque" } CGPROGRAM #pragma surface surf Lambert struct Input { float2 uv_MainTex; float2 uv_BumpMap; float3 viewDir; }; sampler2D _MainTex; sampler2D _BumpMap; float4 _RimColor; float _RimPower; void surf (Input IN, inout SurfaceOutput o) { o.Albedo = tex2D (_MainTex, IN.uv_MainTex).rgb; o.Normal = UnpackNormal (tex2D (_BumpMap, IN.uv_BumpMap)); half rim = 1.0 - saturate(dot (normalize(IN.viewDir), o.Normal)); o.Emission = _RimColor.rgb * pow (rim, _RimPower); } ENDCG } Fallback "Diffuse" }
原理简单说一下,主要是用来计算边缘光照的,首先通过视线与法线的夹角来找到模型的边缘,然后再根据距离的远近来控制发射光的强度。
half rim = 1.0 - saturate(dot (normalize(IN.viewDir), IN.worldNormal)); o.Emission = _RimColor.rgb * pow (rim, _RimPower);
胖胖的螃蟹
这个效果原理很简单,就是将顶点位置沿着法线方向移动一定的距离。
Shader "Custom/Test4" { Properties { _MainTex ("Texture", 2D) = "white" {} _Amount ("Extrusion Amount", Range(-1,1)) = 0.5 } SubShader { Tags { "RenderType" = "Opaque" } CGPROGRAM #pragma surface surf Lambert vertex:vert struct Input { float2 uv_MainTex; }; float _Amount; void vert (inout appdata_full v) { v.vertex.xyz += v.normal * _Amount; } sampler2D _MainTex; void surf (Input IN, inout SurfaceOutput o) { o.Albedo = tex2D (_MainTex, IN.uv_MainTex).rgb; } ENDCG } Fallback "Diffuse" }
确实胖了,但是..怎么画框框的地方怎么有点怪怪的? 其实是mesh的问题,这个从游戏里面提取的模型,三角面可能并不好,比如这个提取的mesh网格九没有封闭。那就换一个好了!
从Dota2的官网下一个旱地神牛的模型下来,导入进来,给他同样的shader,结果如下。
高富帅瞬间变蠢萌娃有木有!0成本把写实风格的模型变成Q版风格。
Vertex modifier function
在surface shader中也可以加入 vetex shader.
方法就是在声明的时候添加一个字段 vertex:xxx,比如
#pragma surface surf Lambert vertex:vert
然后定义好vert函数就可以了。vertex shading的过程会在surface函数之前进行。下面的例子是将法线渲染出来(叠加在原来的颜色上)。
Shader "Custom/test5" { Properties { _MainTex ("Texture", 2D) = "white" {} } SubShader { Tags { "RenderType" = "Opaque" } CGPROGRAM #pragma surface surf Lambert vertex:vert struct Input { float2 uv_MainTex; float3 customColor; }; void vert (inout appdata_full v, out Input o) { UNITY_INITIALIZE_OUTPUT(Input,o); o.customColor = abs(v.normal); } sampler2D _MainTex; void surf (Input IN, inout SurfaceOutput o) { o.Albedo = tex2D (_MainTex, IN.uv_MainTex).rgb; o.Albedo *= IN.customColor; } ENDCG } Fallback "Diffuse" }
之前的Rim lighting在可以在vertex shading中计算。
Final Color Modifier
这个就很像fregment shader了,属于pipeline的最后一个阶段。
定义的方式和vertex 的类似,
#pragma surface surf Lambert finalcolor:mycolor
Shader "Custom/test6" { Properties { _MainTex ("Texture", 2D) = "white" {} _ColorTint ("Tint", Color) = (1.0, 0.6, 0.6, 1.0) } SubShader { Tags { "RenderType" = "Opaque" } CGPROGRAM #pragma surface surf Lambert finalcolor:mycolor struct Input { float2 uv_MainTex; }; fixed4 _ColorTint; void mycolor (Input IN, SurfaceOutput o, inout fixed4 color) { color *= _ColorTint; } sampler2D _MainTex; void surf (Input IN, inout SurfaceOutput o) { o.Albedo = tex2D (_MainTex, IN.uv_MainTex).rgb; } ENDCG } Fallback "Diffuse" }
Surface Shader Examples - http://docs.unity3d.com/Manual/SL-SurfaceShaderExamples.html