Contribute correction: The Ray Tracing Demo

 _    _    __   __               ___    
| |  | ||  \ \\/ //   ____      / _ \\  
| |/\| ||   \ ` //   |    \\   / //\ \\ 
|  /\  ||    | ||    | [] ||  |  ___  ||
|_// \_||    |_||    |  __//  |_||  |_||
`-`   `-`    `-`'    |_|`-`   `-`   `-` 
                     `-`