Contribute correction: The Ray Tracing Demo

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