Circle.shader

Shader "Custom/Circle" {
    Properties {
        _MainTex("Main Texture", 2D) = "white" {}
        _Color("Base Color", Color) = (0, 0, 0, 1)
    }
    SubShader {
        Tags {
            "RenderType" = "Opaque"
        }
        LOD 200

        CGPROGRAM

        #pragma surface surf Standard
        #pragma target 3.0

        struct Input {
            float2 uv_MainTex;
        };

        fixed4 _Color;

        void surf(Input IN, inout SurfaceOutputStandard o) {
            fixed4 w = fixed4(1, 1, 1, 1);
            float dist = distance( float2(0.5, 0.5), IN.uv_MainTex)*10;
            float val = abs(sin(dist*3.0));
            o.Albedo = val > 0.98 ? w : _Color ;
        }

        ENDCG
    }
    Fallback "Diffuse"
}