Unity3d Tutorial Shader: The 25th lecture Blur

reprinted from the Wind Yu Chong Unity3d Tutorial CollegeBlur Fuzzy actually understand the later very simple. The core principle is
The 1-point color does not use the color of the point, but instead uses the mean of all points around that point
(1) Determine the pickup range, such as 3 pixels around or 10 pixels around
(2) Determine the weight of each point, which is also the origin of the Gaussian blur, the main color distribution is a normal distribution, that is, Gaussian distribution.


Example 1: The simplest blur
(1) New scene, plane a sticker on top
(2) plane on the shader as follows

Shader "Custom/objectblur" {Properties {_maintex ("Base (RGB)", 2D) = "white" {}} subshader { tags{"Queue" = "Transparent"} pass {Cgprogram #pragma vertex vert #pr            Agma fragment Frag #include "unitycg.cginc" sampler2d _maintex;            FLOAT4 _maintex_st;                       float Uvoffset;                struct V2F {float4 pos:sv_position;            FLOAT2 uv:texcoord0;            } ;                v2f Vert (Appdata_base v) {v2f o;                O.pos = Mul (Unity_matrix_mvp,v.vertex);                O.UV = Transform_tex (V.texcoord,_maintex);            return o; } float4 Frag (v2f i): COLOR {float4 S1 = tex2d (_maintex,i.uv + FLOAT2 (uvoffset,0.0                0));                FLOAT4 s2 = tex2d (_maintex,i.uv + float2 (-uvoffset,0.00)); FLOAT4 s3 = tex2d (_maintex,i.uv+ FLOAT2 (0.00,uvoffset));                               FLOAT4 S4 = tex2d (_maintex,i.uv + float2 (0.00,-uvoffset));                FLOAT4 Texcol = tex2d (_MAINTEX,I.UV);                               FLOAT4 OUTP;                float pct=0.2;                OUTP = texcol* (1-pct*4) + s1* pct + s2* pct+ s3* pct + s4* pct;            return OUTP; } ENDCG}}}

　　

As well as the BlurManager.cs script, as follows

Using unityengine;using System.collections;public class Blurmanager:monobehaviour {    private float length =3f;    private float showTime = -100;    private float hidetime = -100;    void Update () {        if (showTime >0)        {            ShowTime-= time.deltatime;            Shader.setglobalfloat ("Uvoffset", (showtime/length) * 0.005f);        }               if (hidetime >0)        {            Hidetime-= time.deltatime;            Shader.setglobalfloat ("Uvoffset", (1-hidetime/length) * 0.005f);        }    }       void Ongui ()    {        if (GUI. button (new Rect (0,0,100,50), "Show"))        {            showTime = length;        }               if (GUI. button (new Rect (100,0,100,50), "Hide"))        {            hidetime = length;}}    }

　　

After running, click the Show button, the graph will clear from the blur, click the Hide button will be blurred from the clear.
This is basically the simplest blur, take this point and its up and down around the 4 offset point. The weights of each point are 0.2. UV offset from 0 to 0.005
The effect is good.

Original


The effect after blurring



Reference articles

Unity3d Tutorial Shader: The 25th lecture Blur