c# – How to create fallout intensity on a generated mesh in Unity?

So I was able to generate a circle mesh in Unity to basically see the other characters when they are inside of it, and hide the characters when they are outside of it, and partially hide and show the character if they are partially in or outside of it. Below is an image of what I was able to generate, but the thing is, the edges are very sharp and I would like to have some Fallout Intensity on the mesh. Just like with Lights in Unity, where they have a fallout intensity at the edge of the lights.

Image of Generated Mesh
enter image description here

As you can see, the edges of the mesh are very sharp and thats not the kind of effect am after, I would like to add some fallout to that, and adjust it.

Here is The Code That Generates The Mesh

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class FieldOfView : MonoBehaviour {

    public float fieldOfView = 360f;
    public int numberEdges = 360;
    public float initalAngle = 0;
    public float visionDistance = 8f;
    public LayerMask layerMask;

    private Mesh mesh;
    private Vector3 origin;

    private void Start()
    {
        mesh = new Mesh();
        GetComponent<MeshFilter>().mesh = mesh;
        origin = Vector3.zero;
    }

    private void LateUpdate()
    {
        GenerateUpdateMesh();
    }

    private void GenerateUpdateMesh()
    {
        float actualAngle = initalAngle;
        float incrementAngle = fieldOfView / numberEdges;

        Vector3() vertices = new Vector3(numberEdges + 1);
        int() triangles = new int(numberEdges * 3);

        vertices(0) = origin;

        int verticeIndex = 1;
        int triangleIndex = 0;

        for (int i = 0; i < numberEdges; i++)
        {
            Vector3 actualVertices;
            RaycastHit2D raycastHit2D = Physics2D.Raycast(origin, GetVectorFromAngle(actualAngle), visionDistance, layerMask);
            if (raycastHit2D.collider == null)
            {
                // No hit
                actualVertices = origin + GetVectorFromAngle(actualAngle) * visionDistance;
            }
            else
            {
                // Hit object
                actualVertices = raycastHit2D.point;
            }

            vertices(verticeIndex) = actualVertices;

            if (i > 0)
            {
                triangles(triangleIndex + 0) = 0;
                triangles(triangleIndex + 1) = verticeIndex - 1;
                triangles(triangleIndex + 2) = verticeIndex;

                triangleIndex += 3;
            }

            verticeIndex++;
            actualAngle -= incrementAngle;
        }

        // We form the last triangle
        triangles(triangleIndex + 0) = 0;
        triangles(triangleIndex + 1) = verticeIndex - 1;
        triangles(triangleIndex + 2) = 1;


        mesh.vertices = vertices;
        mesh.triangles = triangles;
    }

    Vector3 GetVectorFromAngle(float angle)
    {
        float angleRad = angle * (Mathf.PI / 180f);
        return new Vector3(Mathf.Cos(angleRad), Mathf.Sin(angleRad));
    }

    public void SetOrigin(Vector3 newOrigin)
    {
        origin = newOrigin;
    }
}

What do I do here to add some Fallout Intensity? All the help is really appreciated. And Thank you in advance.