简单的搞了个UI描边效果,需求简单,UI的贴图都是规整的,所以整了个简单的效果进行尝试,不通用
shader代码
// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)
Shader "UI/SpriteOutline"
{
Properties
{
[PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
_Color ("Tint", Color) = (1,1,1,1)
_ColorLine("Line", 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
[PowerSlider(5)] _Test("Test",Range(0.8,5)) = 1
}
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_local _ UNITY_UI_CLIP_RECT
#pragma multi_compile_local _ UNITY_UI_ALPHACLIP
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;
half4 mask : TEXCOORD2;
UNITY_VERTEX_OUTPUT_STEREO
};
sampler2D _MainTex;
fixed4 _Color;
fixed4 _ColorLine;
fixed4 _TextureSampleAdd;
float4 _ClipRect;
float4 _MainTex_ST;
float _MaskSoftnessX;
float _MaskSoftnessY;
float _Test;
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 = float4(v.texcoord.x, v.texcoord.y, maskUV.x, maskUV.y);
OUT.mask = half4(v.vertex.xy * 2 - clampedRect.xy - clampedRect.zw, 0.25 / (0.25 * half2(_MaskSoftnessX, _MaskSoftnessY) + abs(pixelSize.xy)));
OUT.color = v.color * _Color;
return OUT;
}
fixed4 frag(v2f IN) : SV_Target
{
half4 color = (tex2D(_MainTex, IN.texcoord)) * IN.color;
#ifdef UNITY_UI_CLIP_RECT
half2 m = saturate((_ClipRect.zw - _ClipRect.xy - abs(IN.mask.xy)) * IN.mask.zw);
color.a *= m.x * m.y;
#endif
float2 dir = IN.texcoord - float2(0.5, 0.5);
dir = float2(0.5, 0.5) + dir * _Test;
half4 color2 = (tex2D(_MainTex, dir)) * IN.color;
#ifdef UNITY_UI_ALPHACLIP
clip (color.a - 0.001);
#endif
_ColorLine.a = color.a;
half4 color3 = lerp(_ColorLine,color2,color2.a);
return color3;
}
ENDCG
}
}
}
实现的思路就是用uv相对于uv的中心点做了缩放,让贴上来的图在ui平面的表现上,产生了相对于中心店的大小偏差,求出了图片的粗糙边缘
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