Unity Shader:闪烁

还是一样的分为UI闪烁和物体闪烁，其中具体可分为：UI闪烁、物体闪烁与半透明闪烁

1，UI闪烁

对于UI 还是一样的，改写UI本身的shader：

Shader "UI/YydUIShanShder"
{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[Toggle(UNITY_UI_ALPHACLIP)] _UseUIAlphaClip("Use Alpha Clip", Float) = 0[Toggle]_Switch("Switch", Float) = 0_value("Speed",Range(1,3)) = 1_overlayCol("OtherColor",Color) = (0.2146,1,0,0.6039)}SubShader{Tags{"Queue" = "Transparent""IgnoreProjector" = "True""RenderType" = "Transparent""PreviewType" = "Plane""CanUseSpriteAtlas" = "True"}Stencil{Ref[_Stencil]Comp[_StencilComp]Pass[_StencilOp]ReadMask[_StencilReadMask]WriteMask[_StencilWriteMask]}Cull OffLighting OffZWrite OffZTest[unity_GUIZTestMode]Blend SrcAlpha OneMinusSrcAlphaColorMask[_ColorMask]Pass{Name "Default"CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 2.0#include "UnityCG.cginc"
#include "UnityUI.cginc"#pragma multi_compile_local _ UNITY_UI_CLIP_RECT
#pragma multi_compile_local _ UNITY_UI_ALPHACLIPstruct 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;half4  mask : TEXCOORD2;UNITY_VERTEX_OUTPUT_STEREO};sampler2D _MainTex;fixed4 _Color;fixed4 _TextureSampleAdd;float4 _ClipRect;float4 _MainTex_ST;float _UIMaskSoftnessX;float _UIMaskSoftnessY;float _value;float4 _overlayCol;half _Switch;v2f vert(appdata_t v){v2f OUT;UNITY_SETUP_INSTANCE_ID(v);UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(OUT);float4 vPosition = UnityObjectToClipPos(v.vertex);OUT.worldPosition = v.vertex;OUT.vertex = vPosition;float2 pixelSize = vPosition.w;pixelSize /= float2(1, 1) * abs(mul((float2x2)UNITY_MATRIX_P, _ScreenParams.xy));float4 clampedRect = clamp(_ClipRect, -2e10, 2e10);float2 maskUV = (v.vertex.xy - clampedRect.xy) / (clampedRect.zw - clampedRect.xy);OUT.texcoord = TRANSFORM_TEX(v.texcoord.xy, _MainTex);OUT.mask = half4(v.vertex.xy * 2 - clampedRect.xy - clampedRect.zw, 0.25 / (0.25 * half2(_UIMaskSoftnessX, _UIMaskSoftnessY) + abs(pixelSize.xy)));OUT.color = v.color * _Color;return OUT;}fixed4 frag(v2f IN) : SV_Target{half4 color = IN.color * (tex2D(_MainTex, IN.texcoord) + _TextureSampleAdd);#ifdef UNITY_UI_CLIP_RECThalf2 m = saturate((_ClipRect.zw - _ClipRect.xy - abs(IN.mask.xy)) * IN.mask.zw);color.a *= m.x * m.y;
#endif#ifdef UNITY_UI_ALPHACLIPclip(color.a - 0.001);
#endifhalf _g = dot(color.rgb, unity_ColorSpaceLuminance);//这部分是自定义处理的if (_Switch == 1){fixed4 col = _overlayCol;float t = abs(sin(_Time.w * _value));col.a = lerp(0, _overlayCol.a, t);color = lerp(color, col, col.a);//将col叠加在color上}return color;}ENDCG}}
}

  实现原理我们可以理解为，在原有的图片上，叠加了一层会随着时间变化而变化透明度的纯色。

  和原image的shader相比，基本没做太大改动。只是为了实现闪烁效果，自定义了如下部分：

//这部分是自定义处理的if (_Switch == 1){fixed4 col = _overlayCol;float t = abs(sin(_Time.w * _value));col.a = lerp(0, _overlayCol.a, t);color = lerp(color, col, col.a);//将col叠加在color上}

2，物体闪烁

  原理相同，实现代码如下：

Shader "YaDong/YydShanShader"
{Properties{_MainTex("Texture", 2D) = "white" {}[Header(twinkle)]_twinkleCol("闪光色",Color) = (0.7735,0.7735,0.7735,1)_twinkleValue("闪烁 Speed",float) = 1_middleValue("中间值",float) = 0.5_volatilityValue("波动",float) = 0.6}SubShader{Tags { "RenderType" = "Opaque" }LOD 100Pass{CGPROGRAM#pragma vertex vert#pragma fragment frag// make fog work//#pragma multi_compile_fog#include "UnityCG.cginc"struct appdata{float4 vertex : POSITION;float2 uv : TEXCOORD0;};struct v2f{float2 uv : TEXCOORD0;//UNITY_FOG_COORDS(1)float4 vertex : SV_POSITION;};sampler2D _MainTex, _YydChangeInterval;float4 _MainTex_ST;float4 _twinkleCol;float _twinkleValue;float _middleValue;float _volatilityValue;v2f vert(appdata v){v2f o;o.vertex = UnityObjectToClipPos(v.vertex);o.uv = TRANSFORM_TEX(v.uv, _MainTex);// UNITY_TRANSFER_FOG(o,o.vertex);return o;}fixed4 frag(v2f i) : SV_Target{// sample the texturefixed4 col = tex2D(_MainTex, i.uv);float t = abs(sin(_Time.w * _twinkleValue)* _volatilityValue)+ _middleValue;// +0.5;col.rgb = lerp(col.rgb, saturate(col.rgb + _twinkleCol.rgb), t);return col;}ENDCG}}
}

3，纯色半透明闪烁

  与上述物体闪烁不同的是，这个只是在颜色基础上加了半透明闪烁，实现代码如下：

Shader "YaDong/YydGreenShader"
{Properties{_MainTex("Texture", 2D) = "white" {}_value("速度",Range(1,3)) = 1_overlayCol("叠加色",Color) = (0.2146,1,0,0.6039)}SubShader{//Tags { "RenderType" = "Opaque"  }Tags { "Queue" = "Transparent" "RenderType" = "Transparent" }zWrite offblend srcAlpha one//LOD 100Pass{CGPROGRAM#pragma vertex vert#pragma fragment frag// make fog work//#pragma multi_compile_fog#include "UnityCG.cginc"struct appdata{float4 vertex : POSITION;float2 uv : TEXCOORD0;};struct v2f{float2 uv : TEXCOORD0;//UNITY_FOG_COORDS(1)float4 vertex : SV_POSITION;};sampler2D _MainTex, _YydChangeInterval;float4 _MainTex_ST;float _value;float4 _overlayCol;v2f vert(appdata v){v2f o;o.vertex = UnityObjectToClipPos(v.vertex);o.uv = TRANSFORM_TEX(v.uv, _MainTex);// UNITY_TRANSFER_FOG(o,o.vertex);return o;}fixed4 frag(v2f i) : SV_Target{fixed4 col = _overlayCol;float t = abs(sin(_Time.w * _value));col.a = lerp(0.3, _overlayCol.a, t);return col;}ENDCG}}
}