Unity 毛玻璃效果（UGUI）—高斯模糊
发表于2017-07-15
因为Unity 提供了GrabPass，可以在Shader中很方便的拿到Panel下面的图像，即_GrabTexture。
Shader "Custom/SimpleGrabPassBlur" ｛
Properties ｛
_Color ("Main Color", Color) = (1,1,1,1)
_BumpAmt ("Distortion", Range (0,128)) = 10
_MainTex ("Tint Color (RGB)", 2D) = "white" ｛｝
_BumpMap ("Normalmap", 2D) = "bump" ｛｝
_Size ("Size", Range(0, 20)) = 1
｝
Category ｛
// We must be transparent, so other objects are drawn before this one.
Tags ｛ "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Opaque" ｝
SubShader ｛
// Horizontal blur
GrabPass ｛
Tags ｛ "LightMode" = "Always" ｝
｝
Pass ｛
Tags ｛ "LightMode" = "Always" ｝
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
struct appdata_t ｛
float4 vertex : POSITION;
float2 texcoord: TEXCOORD0;
｝;
struct v2f ｛
float4 vertex : POSITION;
float4 uvgrab : TEXCOORD0;
｝;
v2f vert (appdata_t v) ｛
v2f o;
o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
#if UNITY_UV_STARTS_AT_TOP
float scale = -1.0;
#else
float scale = 1.0;
#endif
o.uvgrab.xy = (float2(o.vertex.x, o.vertex.y*scale) o.vertex.w) * 0.5;
o.uvgrab.zw = o.vertex.zw;
return o;
｝
sampler2D _GrabTexture;
float4 _GrabTexture_TexelSize;
float _Size;
half4 frag( v2f i ) : COLOR ｛
// half4 col = tex2Dproj( _GrabTexture, UNITY_PROJ_COORD(i.uvgrab));
// return col;
half4 sum = half4(0,0,0,0);
#define GRABPIXEL(weight,kernelx) tex2Dproj( _GrabTexture, UNITY_PROJ_COORD(float4(i.uvgrab.x _GrabTexture_TexelSize.x * kernelx*_Size, i.uvgrab.y, i.uvgrab.z, i.uvgrab.w))) * weight
sum = GRABPIXEL(0.05, -4.0);
sum = GRABPIXEL(0.09, -3.0);
sum = GRABPIXEL(0.12, -2.0);
sum = GRABPIXEL(0.15, -1.0);
sum = GRABPIXEL(0.18, 0.0);
sum = GRABPIXEL(0.15, 1.0);
sum = GRABPIXEL(0.12, 2.0);
sum = GRABPIXEL(0.09, 3.0);
sum = GRABPIXEL(0.05, 4.0);
return sum;
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ENDCG
｝
// Vertical blur
GrabPass ｛
Tags ｛ "LightMode" = "Always" ｝
｝
Pass ｛
Tags ｛ "LightMode" = "Always" ｝
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
struct appdata_t ｛
float4 vertex : POSITION;
float2 texcoord: TEXCOORD0;
｝;
struct v2f ｛
float4 vertex : POSITION;
float4 uvgrab : TEXCOORD0;
｝;
v2f vert (appdata_t v) ｛
v2f o;
o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
#if UNITY_UV_STARTS_AT_TOP
float scale = -1.0;
#else
float scale = 1.0;
#endif
o.uvgrab.xy = (float2(o.vertex.x, o.vertex.y*scale) o.vertex.w) * 0.5;
o.uvgrab.zw = o.vertex.zw;
return o;
｝
sampler2D _GrabTexture;
float4 _GrabTexture_TexelSize;
float _Size;
half4 frag( v2f i ) : COLOR ｛
// half4 col = tex2Dproj( _GrabTexture, UNITY_PROJ_COORD(i.uvgrab));
// return col;
half4 sum = half4(0,0,0,0);
#define GRABPIXEL(weight,kernely) tex2Dproj( _GrabTexture, UNITY_PROJ_COORD(float4(i.uvgrab.x, i.uvgrab.y _GrabTexture_TexelSize.y * kernely*_Size, i.uvgrab.z, i.uvgrab.w))) * weight
//G(X) = (1/(sqrt(2*PI*deviation*deviation))) * exp(-(x*x / (2*deviation*deviation)))
sum = GRABPIXEL(0.05, -4.0);
sum = GRABPIXEL(0.09, -3.0);
sum = GRABPIXEL(0.12, -2.0);
sum = GRABPIXEL(0.15, -1.0);
sum = GRABPIXEL(0.18, 0.0);
sum = GRABPIXEL(0.15, 1.0);
sum = GRABPIXEL(0.12, 2.0);
sum = GRABPIXEL(0.09, 3.0);
sum = GRABPIXEL(0.05, 4.0);
return sum;
｝
ENDCG
｝
// Distortion
GrabPass ｛
Tags ｛ "LightMode" = "Always" ｝
｝
Pass ｛
Tags ｛ "LightMode" = "Always" ｝
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
struct appdata_t ｛
float4 vertex : POSITION;
float2 texcoord: TEXCOORD0;
｝;
struct v2f ｛
float4 vertex : POSITION;
float4 uvgrab : TEXCOORD0;
float2 uvbump : TEXCOORD1;
float2 uvmain : TEXCOORD2;
｝;
float _BumpAmt;
float4 _BumpMap_ST;
float4 _MainTex_ST;
v2f vert (appdata_t v) ｛
v2f o;
o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
#if UNITY_UV_STARTS_AT_TOP
float scale = -1.0;
#else
float scale = 1.0;
#endif
o.uvgrab.xy = (float2(o.vertex.x, o.vertex.y*scale) o.vertex.w) * 0.5;
o.uvgrab.zw = o.vertex.zw;
o.uvbump = TRANSFORM_TEX( v.texcoord, _BumpMap );
o.uvmain = TRANSFORM_TEX( v.texcoord, _MainTex );
return o;
｝
fixed4 _Color;
sampler2D _GrabTexture;
float4 _GrabTexture_TexelSize;
sampler2D _BumpMap;
sampler2D _MainTex;
half4 frag( v2f i ) : COLOR ｛
// calculate perturbed coordinates
half2 bump = UnpackNormal(tex2D( _BumpMap, i.uvbump )).rg; // we could optimize this by just reading the x y without reconstructing the Z
float2 offset = bump * _BumpAmt * _GrabTexture_TexelSize.xy;
i.uvgrab.xy = offset * i.uvgrab.z i.uvgrab.xy;
half4 col = tex2Dproj( _GrabTexture, UNITY_PROJ_COORD(i.uvgrab));
half4 tint = tex2D( _MainTex, i.uvmain ) * _Color;
return col * tint;
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ENDCG
｝
｝
｝
｝ 使用：
新建Panel->去掉Source Image->material处添加此shader的材质球。该Panel即可对背后的显示实现高斯模糊效果。
来自：http://www.igiven.com/?p=632