Procedural Polygon Collider 2D

I am working a procedural terrain system, which can be destroyed and build.
The problem I am having now, is that the collider does not match the terrain.



The way I am getting points, is by checking if a pixel as 1 or 2 neighbor pixels. Only then the pixel's location will be used as a point for the collider.

Then I sort the List of Vector2 locations in a clockwise way.

This sorting works when the points are in a certain way.

Code (CSharp):

1. //from: https://pastebin.com/1RkaP28U
2. //from: https://answers.unity.com/questions/877169/vector2-array-sort-clockwise.html
3. public class ClockwiseComparer : IComparer<Vector2> {
4.     private Vector2 m_Origin;
5.  
6.     public ClockwiseComparer(Vector2 origin) {
7.         m_Origin = origin;
8.     }
9.  
10.     public int Compare(Vector2 first, Vector2 second) {
11.         return IsClockwise(first, second, m_Origin);
12.     }
13.  
14.     public static int IsClockwise(Vector2 first, Vector2 second, Vector2 origin) {
15.         if (first == second)
16.             return 0;
17.  
18.         Vector2 firstOffset = first - origin;
19.         Vector2 secondOffset = second - origin;
20.  
21.         float angle1 = Mathf.Atan2(firstOffset.x, firstOffset.y);
22.         float angle2 = Mathf.Atan2(secondOffset.x, secondOffset.y);
23.  
24.         if (angle1 < angle2)
25.             return -1;
26.  
27.         if (angle1 > angle2)
28.             return 1;
29.  
30.         return (firstOffset.sqrMagnitude < secondOffset.sqrMagnitude) ? -1 : 1;
31.     }
32. }

Can someone help me with this, or maybe suggest a different method of doing this.

 

All these red points will become part of the collider.



And because terrain can be destroyed, this might also happen

 

Take a peak at this https://unity3d.com/learn/tutorials/projects/procedural-cave-generation-tutorial/marching-squares