public static void BuildPoly(D2dPolygonColliderCell cell, List <PolygonCollider2D> unusedColliders, GameObject child, float detail)
        {
            cell.Clear(unusedColliders);

            // Find the start points of paths
            for (var i = 0; i < pointCount; i++)
            {
                var point = points[i];

                if (point.Used == false)
                {
                    Trace(point);
                    WeldLines();
                    OptimizeEdges(detail);

                    cell.AddPolygon(unusedColliders, child, ExtractPoints(1));
                }
            }

            // Remove unused polygons
            cell.Trim();
        }
 private void Mark(D2dPolygonColliderCell cell)
 {
     cell.Clear(unusedColliders);
 }