Unity_Shader_用Shader绘制攻击范围的圆圈

Shader "Custom/Circle" {
Properties {
_Color ("Color", Color) = (1,1,1,1)
_Width("RoundWidth", float) = 0.03
}

SubShader {
Pass {
ZTest Off
ZWrite Off
ColorMask 0
}

Pass {
Blend SrcAlpha OneMinusSrcAlpha
CGPROGRAM

#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"

struct v2f {
float4 pos : SV_POSITION;
float4 oPos : TEXCOORD1;
};
fixed4 _Color;
int _Width;

float4 _MainTex_ST;
v2f vert (appdata_base v){
v2f o;
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
o.oPos = v.vertex;
return o;
}

fixed4 frag(v2f i) : COLOR{
float dis = sqrt(i.oPos.x * i.oPos.x + i.oPos.y * i.oPos.y);
float maxDistance = 0.05;
if(dis > 0.5){
discard;
}else{
float ringWorldRange = _Object2World[0][0];
float minDistance =(ringWorldRange * 0.43 - _Width)/ringWorldRange * 0.9;
if(dis < minDistance){
discard;
}
_Color.a = (dis - minDistance)/(1 - minDistance) * 0.9;
}
return _Color;
}

ENDCG
}
}

FallBack "Diffuse"

}