unityShader物体表面流光效果
本文转载自http://blog.csdn.net/lyh916/article/details/51831720
参考链接：http://liweizhaolili.blog.163.com/blog/static/162307442012726111843408/
效果图：
1.首先，导入unity自带的模型，如下图，它使用的是StandardSpecular这个shader，具体的实现可以从unity官网中下载看看。它的实现比较复杂，这里我们把它替换为我们自己写的shader，方便我们去控制。对于法线贴图，注意要设置Texture Type为Normal map。
下面这个shader是漫反射+高光+法线贴图：
Shader "Custom/Light"
{
Properties
{
_MainColor ("主颜色", Color) = (0.5, 0.5, 0.5, 1)
_NormalTex ("法线贴图", 2D) = "white" {}
_Specular ("高光颜色", Color) = (1, 1, 1, 1)
_Gloss ("高光系数", Range(8, 256)) = 20
}
SubShader
{
Tags { "LightMode" = "ForwardBase" }
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "Lighting.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
float3 normal : NORMAL;
float4 tangent : TANGENT;
};
struct v2f
{
float4 vertex : SV_POSITION;
float2 uv : TEXCOORD0;
float3 lightDir : TEXCOORD1;
float3 viewDir : TEXCOORD2;
};
fixed4 _MainColor;
sampler2D _NormalTex;
fixed4 _Specular;
float _Gloss;
v2f vert (appdata v)
{
v2f o;
o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
o.uv = v.uv;
TANGENT_SPACE_ROTATION;
//rotation是使模型空间转为切线空间的矩阵
o.lightDir = mul(rotation, ObjSpaceLightDir(v.vertex)).xyz;
o.viewDir = mul(rotation, ObjSpaceViewDir(v.vertex)).xyz;
return o;
}
fixed4 frag (v2f i) : SV_Target
{
fixed3 tangentLightDir = normalize(i.lightDir);
fixed3 tangentViewDir = normalize(i.viewDir);
fixed4 packedNormal = tex2D(_NormalTex, i.uv);
fixed3 tangentNormal = UnpackNormal(packedNormal);
//漫反射
fixed3 diffuse = _LightColor0.rgb * _MainColor.rgb * saturate(dot(tangentNormal, tangentViewDir));
//Blinn-Phong高光光照模型，相对于普通的Phong高光模型，会更加光
fixed3 halfDir = normalize(tangentLightDir + tangentViewDir);
fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(saturate(dot(tangentNormal, halfDir)), _Gloss);
return fixed4(diffuse + specular, 1);
}
ENDCG
}
}
}
两个shader的对比，左边是模型原本的shader，右边是上面的shader。左边的有一种泥瓦的质感，而右边的有一种金属的质感。
2.从效果图中，我们可以发现有边缘光的效果，因此先加上。
Shader "Custom/Light"
{
Properties
{
_MainColor ("主颜色", Color) = (0.5, 0.5, 0.5, 1)
_NormalTex ("法线贴图", 2D) = "white" {}
_Specular ("高光颜色", Color) = (1, 1, 1, 1)
_Gloss ("高光系数", Range(8, 256)) = 20
_RimColor ("边缘颜色", Color) = (1, 0, 0, 1)
_RimPower ("边缘颜色强度", Range(0.1, 1)) = 1
}
SubShader
{
Tags { "LightMode" = "ForwardBase" }
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "Lighting.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
float3 normal : NORMAL;
float4 tangent : TANGENT;
};
struct v2f
{
float4 vertex : SV_POSITION;
float2 uv : TEXCOORD0;
float3 lightDir : TEXCOORD1;
float3 viewDir : TEXCOORD2;
};
fixed4 _MainColor;
sampler2D _NormalTex;
fixed4 _Specular;
float _Gloss;
fixed4 _RimColor;
half _RimPower;
v2f vert (appdata v)
{
v2f o;
o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
o.uv = v.uv;
TANGENT_SPACE_ROTATION;
//rotation是使模型空间转为切线空间的矩阵
o.lightDir = mul(rotation, ObjSpaceLightDir(v.vertex)).xyz;
o.viewDir = mul(rotation, ObjSpaceViewDir(v.vertex)).xyz;
return o;
}
fixed4 frag (v2f i) : SV_Target
{
fixed3 tangentLightDir = normalize(i.lightDir);
fixed3 tangentViewDir = normalize(i.viewDir);
fixed4 packedNormal = tex2D(_NormalTex, i.uv);
fixed3 tangentNormal = UnpackNormal(packedNormal);
//漫反射
fixed3 diffuse = _LightColor0.rgb * _MainColor.rgb * saturate(dot(tangentNormal, tangentViewDir));
//Blinn-Phong高光光照模型，相对于普通的Phong高光模型，会更加光
fixed3 halfDir = normalize(tangentLightDir + tangentViewDir);
fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(saturate(dot(tangentNormal, halfDir)), _Gloss);
//边缘颜色，对于法线和观察方向，只要在同一坐标系下即可
fixed dotProduct = 1 - saturate(dot(tangentNormal, tangentViewDir));
fixed3 rim = _RimColor.rgb * pow(dotProduct, 1 / _RimPower);
return fixed4(diffuse + specular + rim, 1);
}
ENDCG
}
}
}
3.接着就需要用到遮罩效果，这里我用到了下面这张遮罩图。分析一下我们的效果图，它的边缘光是流动的，对于某一个位置的边缘光，随着时间的变化，它是在有光与无光这两个状态不断变化的，而看一下我们的遮罩图，以y轴方向来说，它也是黑白两种状态的切换，通过对遮罩图的取样，就能对边缘光进行控制了。再说一点，如果我们把遮罩图改为全白的，那么就是我们上方那种效果了，不会发生流动。
Shader "Custom/Light"
{
Properties
{
_MainColor ("主颜色", Color) = (0.5, 0.5, 0.5, 1)
_NormalTex ("法线贴图", 2D) = "white" {}
_Specular ("高光颜色", Color) = (1, 1, 1, 1)
_Gloss ("高光系数", Range(8, 256)) = 20
_RimColor ("边缘颜色", Color) = (1, 0, 0, 1)
_RimPower ("边缘颜色强度", Range(0.1, 1)) = 1
_MaskTex ("光遮罩图", 2D) = "white" {}
_MoveDir ("边缘光移动方向", Range(-1, 1)) = 1
}
SubShader
{
Tags { "LightMode" = "ForwardBase" }
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "Lighting.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
float3 normal : NORMAL;
float4 tangent : TANGENT;
};
struct v2f
{
float4 vertex : SV_POSITION;
float2 uv : TEXCOORD0;
float3 lightDir : TEXCOORD1;
float3 viewDir : TEXCOORD2;
};
fixed4 _MainColor;
sampler2D _NormalTex;
fixed4 _Specular;
float _Gloss;
fixed4 _RimColor;
half _RimPower;
sampler2D _MaskTex;
fixed _MoveDir;
v2f vert (appdata v)
{
v2f o;
o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
o.uv = v.uv;
TANGENT_SPACE_ROTATION;
//rotation是使模型空间转为切线空间的矩阵
o.lightDir = mul(rotation, ObjSpaceLightDir(v.vertex)).xyz;
o.viewDir = mul(rotation, ObjSpaceViewDir(v.vertex)).xyz;
return o;
}
fixed4 frag (v2f i) : SV_Target
{
fixed3 tangentLightDir = normalize(i.lightDir);
fixed3 tangentViewDir = normalize(i.viewDir);
fixed4 packedNormal = tex2D(_NormalTex, i.uv);
fixed3 tangentNormal = UnpackNormal(packedNormal);
//漫反射
fixed3 diffuse = _LightColor0.rgb * _MainColor.rgb * saturate(dot(tangentNormal, tangentViewDir));
//Blinn-Phong高光光照模型，相对于普通的Phong高光模型，会更加光
fixed3 halfDir = normalize(tangentLightDir + tangentViewDir);
fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(saturate(dot(tangentNormal, halfDir)), _Gloss);
//边缘颜色，对于法线和观察方向，只要在同一坐标系下即可
fixed dotProduct = 1 - saturate(dot(tangentNormal, tangentViewDir));
fixed3 rim = _RimColor.rgb * pow(dotProduct, 1 / _RimPower);
fixed4 maskCol = tex2D(_MaskTex, i.uv + float2(0, _Time.y * _MoveDir));
return fixed4(diffuse + specular + rim * maskCol.rgb, 1);
}
ENDCG
}
}
}
这是unitypackage：
http://pan.baidu.com/s/1mh9T1l2