int current_pos = 0;
for (int row = 1; row < 18; row++)
{
    if (row % 2 != 0)
    {
        // Odd row that has 9 heights
        for (int i = 0; i < 9; i++)
        {
            positionList.Add(new Vector3(vert_x - (column_spacing_9 * i), vert_y + currentMCNK._MCVT.heights[current_pos], vert_z - ((row - 1) * row_spacing)));
            current_pos++;
        }
    }
    else
    {
        // Even row that has 8 heights
        for (int i = 0; i < 8; i++)
        {
            //positionList.Add(new Vector3(vert_x - (column_spacing_8 * i), vert_y - currentMCNK._MCVT.heights[current_pos], vert_z - ((row - 1) * row_spacing)));
            current_pos++;
        }
    }
}