写一个2d描边shader
时间: 2023-03-30 21:01:10 浏览: 74
好的,我可以回答这个问题。2D描边shader可以通过在渲染过程中对边缘进行描边来实现。具体实现方法可以使用Sobel算子或Laplacian算子来检测边缘,并将边缘区域进行描边。同时,可以通过调整描边的颜色、宽度和模糊程度等参数来实现不同的效果。
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用Unity写一个描边shader
下面是一个简单的Unity描边shader的示例代码:
```
Shader "Custom/Outline" {
Properties {
_MainTex ("Texture", 2D) = "white" {}
_OutlineColor ("Outline Color", Color) = (0,0,0,1)
_OutlineWidth ("Outline Width", Range (0.002, 0.1)) = 0.01
}
SubShader {
Tags {"Queue"="Transparent" "RenderType"="Opaque"}
LOD 100
Pass {
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct appdata {
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f {
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};
sampler2D _MainTex;
float4 _MainTex_ST;
float4 _OutlineColor;
float _OutlineWidth;
v2f vert (appdata v) {
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
return o;
}
fixed4 frag (v2f i) : SV_Target {
// sample the texture
fixed4 col = tex2D(_MainTex, i.uv);
// calculate the outline color
fixed4 outline = _OutlineColor;
float2 texelSize = 1.0 / _ScreenParams.xy;
float2 offset[4] = float2[](
float2(texelSize.x, 0),
float2(-texelSize.x, 0),
float2(0, texelSize.y),
float2(0, -texelSize.y)
);
for (int j = 0; j < 4; j++) {
outline += tex2D(_MainTex, i.uv + _OutlineWidth * offset[j]);
}
outline /= 5.0;
// mix the texture and outline color
return lerp(outline, col, col.a);
}
ENDCG
}
}
FallBack "Diffuse"
}
```
这个shader的核心思想是在每个像素周围采样一些颜色,并将它们平均值作为描边颜色。可以通过调整 `_OutlineWidth` 属性来控制描边的宽度,通过调整 `_OutlineColor` 属性来控制描边的颜色。
写一段unity的描边shader
以下是一段简单的Unity描边Shader代码:
```
Shader "Custom/Outline" {
Properties {
_Color ("Color", Color) = (1,1,1,1)
_Thickness ("Thickness", Float) = 0.01
}
SubShader {
Tags {"Queue"="Geometry" "RenderType"="Opaque"}
Pass {
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma geometry geom
struct appdata {
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f {
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};
v2f vert (appdata v) {
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = v.uv;
return o;
}
sampler2D _MainTex;
float4 _MainTex_ST;
float4 frag (v2f i) : SV_Target {
return tex2D(_MainTex, i.uv);
}
[maxvertexcount(3)]
void geom(triangle v2f IN[3], inout TriangleStream<v2f> stream) {
v2f v0 = IN[0];
v2f v1 = IN[1];
v2f v2 = IN[2];
float3 p0 = v0.vertex.xyz;
float3 p1 = v1.vertex.xyz;
float3 p2 = v2.vertex.xyz;
float3 e0 = p1 - p0;
float3 e1 = p2 - p0;
float3 n = cross(e0, e1);
n = normalize(n);
float3 side0 = n * _Thickness;
float3 side1 = n * _Thickness;
float3 side2 = n * _Thickness;
v0.vertex.xyz += side0;
v1.vertex.xyz += side1;
v2.vertex.xyz += side2;
stream.Append(v0);
stream.Append(v1);
stream.Append(v2);
v0.vertex.xyz -= side0 * 2;
v1.vertex.xyz -= side1 * 2;
v2.vertex.xyz -= side2 * 2;
stream.Append(v0);
stream.Append(v1);
stream.Append(v2);
}
ENDCG
}
}
FallBack "Diffuse"
}
```
这段Shader使用了几何Shader来实现描边效果,通过计算每个三