<1>效果图和原图

思路：初始扩散以（）0.5，0）为圆心扩散，计算UV坐标到圆心距离，初始扩散完毕，从下到上改变alpha就好啦

代码：

float2 uv = IN.texcoord.xy;

fixed4 col = IN.color;

float timer = _Time.y;

if (timer > 2.5) {

timer = timer - 2.5;

float h = timer/2 % 1;

if (h - uv.y > 0.2 || h - uv.y < 0)//循环流动

col.a = 0.4;

else {

float val = (1 - (h - uv.y));//0.8~1 

col.a = val*val*val;//扩大0.8~1

}

}

else {

float dis = timer/2 % 1.5;//0-1 UV.Y//初始扩散

float len = length(uv - float2(0.5, 0));

dis = dis - len;

if (dis< 0)

col.a = 0;

if (dis>0)

col.a = 1 - dis>0.4?1-dis:0.4;

}

clip(col.a - 0.01);

完整代码：

// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)

Shader "Tang/UIFlashVertical"

{

Properties

{

[PerRendererData] _MainTex("Sprite Texture", 2D) = "white" {}

_Color("Tint", Color) = (1,1,1,1)

_StencilComp("Stencil Comparison", Float) = 8

_Stencil("Stencil ID", Float) = 0

_StencilOp("Stencil Operation", Float) = 0

_StencilWriteMask("Stencil Write Mask", Float) = 255

_StencilReadMask("Stencil Read Mask", Float) = 255

_ColorMask("Color Mask", Float) = 15

//my member

[Toggle(UNITY_UI_ALPHACLIP)] _UseUIAlphaClip("Use Alpha Clip", Float) = 0

}

SubShader

{

Tags

{

"Queue" = "Transparent"

"IgnoreProjector" = "True"

"RenderType" = "Transparent"

"PreviewType" = "Plane"

"CanUseSpriteAtlas" = "True"

}

Stencil

{

Ref[_Stencil]

Comp[_StencilComp]

Pass[_StencilOp]

ReadMask[_StencilReadMask]

WriteMask[_StencilWriteMask]

}

Cull Off

Lighting Off

ZWrite Off

ZTest[unity_GUIZTestMode]

Blend SrcAlpha OneMinusSrcAlpha

ColorMask[_ColorMask]

Pass

{

Name "Default"

CGPROGRAM

#pragma vertex vert

#pragma fragment frag

#pragma target 2.0

#include "UnityCG.cginc"

#include "UnityUI.cginc"

#pragma multi_compile __ UNITY_UI_ALPHACLIP

#define PI 3.1415926

struct appdata_t

{

float4 vertex : POSITION;

float4 color : COLOR;

float2 texcoord : TEXCOORD0;

UNITY_VERTEX_INPUT_INSTANCE_ID

};

struct v2f

{

float4 vertex : SV_POSITION;

fixed4 color : COLOR;

float2 texcoord : TEXCOORD0;

float4 worldPosition : TEXCOORD1;

UNITY_VERTEX_OUTPUT_STEREO

};

fixed4 _Color;

fixed4 _TextureSampleAdd;

float4 _ClipRect;

v2f vert(appdata_t IN)

{

v2f OUT;

UNITY_SETUP_INSTANCE_ID(IN);

UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(OUT);

OUT.worldPosition = IN.vertex;

OUT.vertex = UnityObjectToClipPos(OUT.worldPosition);

OUT.texcoord = IN.texcoord;

OUT.color = IN.color * _Color;

return OUT;

}

sampler2D _MainTex;

fixed4 frag(v2f IN) : SV_Target

{

float2 uv = IN.texcoord.xy;

fixed4 col = IN.color;

//从下到上 以0.5，0为圆心扩散

float timer = _Time.y;

if (timer > 2.5) {

timer = timer - 2.5;

float h = timer/2 % 1;

if (h - uv.y > 0.2 || h - uv.y < 0)

col.a = 0.4;

else {

float val = (1 - (h - uv.y));

col.a = val*val*val;

}

}

else {

float dis = timer/2 % 1.5;//0-1 UV.Y

float len = length(uv - float2(0.5, 0));

dis = dis - len;

if (dis< 0)

col.a = 0;

if (dis>0)

col.a = 1 - dis>0.4?1-dis:0.4;

}

clip(col.a - 0.01);

half4 color = (tex2D(_MainTex, uv) + _TextureSampleAdd) * col;

color.a *= UnityGet2DClipping(IN.worldPosition.xy, _ClipRect);

#ifdef UNITY_UI_ALPHACLIP

clip(color.a - 0.001);

#endif

return color;

}

ENDCG

}

}

}

 

 

-------------------------------------分割线---------------------------------------

有些效果写到github里面了，我的Github：https://github.com/tianjiuwan