StripUtility.cs

using System.Collections.Generic;
using UnityEngine;

public static class StripUtility
{
    // 1) Remove specified vertices
    // 2) Re-sort remaining verts by angle around the centroid
    // Ensures a consistent winding for a triangle strip after removal
    public static void RemoveAndReorder(ref List<Vector3> verts, List<int> indicesToRemove)
    {
        // Remove unwanted verts (sort indices descending so removal won't shift)
        indicesToRemove.Sort((a, b) => b.CompareTo(a));
        foreach(int i in indicesToRemove)
            if(i >= 0 && i < verts.Count) verts.RemoveAt(i);

        if(verts.Count < 3) return; // Nothing to reorder

        // Compute centroid
        Vector3 center = Vector3.zero;
        for(int i = 0; i < verts.Count; i++)
            center += verts[i];
        center /= verts.Count;

        // Sort by angle around centroid
        verts.Sort((v1, v2) =>
        {
            float a1 = Mathf.Atan2(v1.y - center.y, v1.x - center.x);
            float a2 = Mathf.Atan2(v2.y - center.y, v2.x - center.x);
            return a1.CompareTo(a2);
        });
    }
}