Unity Shader实现UI流光效果

效果：

shader

Shader"UI/Unlit/Flowlight"{Properties{[PerRendererData]_MainTex("Sprite Texture",2D)="white"{}_Color("Tint",Color)=(1,1,1,1)[MaterialToggle]PixelSnap("Pixel snap",float)=0/* Flowlight */_FlowlightColor("Flowlight Color",Color)=(1,0,0,1)_Lengthlitandlar("LangthofLittle and Large",range(0,0.5))=0.005_MoveSpeed("MoveSpeed",float)=5_Power("Power",float)=1_LargeWidth("LargeWidth",range(0,0.005))=0.0035_LittleWidth("LittleWidth",range(0,0.001))=0.002/* --------- */_WidthRate("WidthRate",float)=0_XOffset("XOffset",float)=0_HeightRate("HeightRate",float)=0_YOffset("YOffset",float)=0/* UI */_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)] _UseClipRect ("Use Clip Rect",Float)=0/* -- */}SubShader{Tags{"Queue"="Transparent""IgnoreProjector"="True"// 忽略投影，因为是UI"RenderType"="Transparent""PreviewType"="Plane""CanUseSpriteAtlas"="True"}CullOffLightingOffZWriteOffBlendOneOneMinusSrcAlphaColorMask[_ColorMask]/* UI */Stencil{Ref[_Stencil]Comp[_StencilComp]Pass[_StencilOp]ReadMask[_StencilReadMask]WriteMask[_StencilWriteMask]}Pass{CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma multi_compile _ PIXELSNAP_ON

            #include "UnityCG.cginc"

            struct appdata_t
            {
                float4 vertex :POSITION;
                float4 color :COLOR;
                float2 texcoord :TEXCOORD0;};

            struct v2f
            {
                float4 vertex :SV_POSITION;
                fixed4 color :COLOR;
                half2 texcoord :TEXCOORD0;
                float4 worldPosition:TEXCOORD1;};

            fixed4 _Color;/* Flowlight */float _Power;float _LargeWidth;float _LittleWidth;float _Lengthlitandlar;float _MoveSpeed;
            fixed4 _FlowlightColor;/* --------- */float _UVPosX;

            v2f vert(appdata_t IN){
                v2f OUT;OUT.worldPosition =IN.vertex;OUT.vertex =UnityObjectToClipPos(IN.vertex);OUT.texcoord =IN.texcoord;OUT.color =IN.color * _Color;
                #ifdef PIXELSNAP_ONOUT.vertex =UnityPixelSnap(OUT.vertex);
                #endif

                returnOUT;}

            sampler2D _MainTex;
            float4 _MainTex_ST;float _WidthRate;float _XOffset;float _HeightRate;float _YOffset;

            bool _UseClipRect;
            float4 _ClipRect;float _ClipSoftX;float _ClipSoftY;// fixed _Factor;

            fixed4 frag(v2f IN):SV_Target{
                fixed4 c =tex2D(_MainTex,IN.texcoord);/*使用裁剪*/if(_UseClipRect){
                    float2 factor =float2(0.0,0.0);
                    float2 tempXY =(IN.worldPosition.xy - _ClipRect.xy)/float2(_ClipSoftX, _ClipSoftY)*step(_ClipRect.xy,IN.worldPosition.xy);
                    factor =max(factor, tempXY);
                    float2 tempZW =(_ClipRect.zw -IN.worldPosition.xy)/float2(_ClipSoftX, _ClipSoftY)*step(IN.worldPosition.xy, _ClipRect.zw);
                    factor =min(factor, tempZW);
                    c.a *=clamp(min(factor.x, factor.y),0.0,1.0);}/* Flowlight */// _UVPosX = _XOffset + (fmod(_Time.x * _MoveSpeed, 1) * 2 - 0.5) * _WidthRate;
                _UVPosX = _XOffset +(fmod(_Time.x * _MoveSpeed,1)*2-0.5);// 【-0.5, 1.5f】//标准uvX倾斜// _UVPosX += (IN.texcoord.y - _HeightRate * 0.5 - _YOffset) * 0.2;//以下是计算流光在区域内的强度，根据到标准点的距离的来确定强度，为了使变化更柔和非线性，使用距离平方或者sin函数也可以float lar =pow(1- _LargeWidth * _WidthRate,2);float lit =pow(1- _LittleWidth * _WidthRate,2);//第一道流光，可以累加任意条，如下
                fixed4 cadd = _FlowlightColor *saturate((1-saturate(pow(_UVPosX -IN.texcoord.x,2)))- lar)* _Power /(1- lar);
                cadd += _FlowlightColor *saturate((1-saturate(pow(_UVPosX - _Lengthlitandlar * _WidthRate -IN.texcoord.x,2)))- lit)* _Power /(1- lit);

                c.rgb += cadd.rgb;
                c.rgb *= c.a;return c;}ENDCG}}}