Shader "LightSphere" for Unity

LightSphere.shader

Shader "LightSphere" {
    SubShader {
        Tags { "RenderType" = "Opacity" }
        Cull Off
        Pass {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"

            struct v2f {
                float4 pos: SV_POSITION;
                float2 uv: TEXCOORD0;
                float4 worldPos: TEXCOORD1;
            };

            v2f vert(appdata_base v) {
                v2f o;
                o.pos = UnityObjectToClipPos(v.vertex);
                o.uv = v.texcoord;
                o.worldPos = mul(unity_ObjectToWorld, v.vertex);
                return o;
            }

            fixed4 frag(v2f i): SV_Target {
                float dist = distance(i.worldPos, _WorldSpaceCameraPos);
                dist = int(dist * 10) / 10 / 1000.0;
                return fixed4(
                    i.uv.x % dist / dist,
                    i.uv.y % dist / dist,
                    (dist * 100 % 1),
                    1);
            }
            ENDCG
        }
    }
}