Describir: Part4: Architecture of Form, variations un tube structure

 _____       ___     ______    _    _    _    _      ___     _    _   
|  __ \\    / _ \\  |      \\ | || | || | |  | ||   / _ \\  | || | || 
| |  \ ||  | / \ || |  --  // | || | || | |/\| ||  / //\ \\ | || | || 
| |__/ ||  | \_/ || |  --  \\ | \\_/ || |  /\  || |  ___  ||| \\_/ || 
|_____//    \___//  |______//  \____//  |_// \_|| |_||  |_|| \____//  
 -----`     `---`   `------`    `---`   `-`   `-` `-`   `-`   `---`   
                                                                      
 __   __  
 \ \\/ // 
  \ ` //  
   | ||   
   |_||   
   `-`'