Mechanisms that allow humans to recognize and understand 2D drawings in 3D have long been actively studied in the fields of artificial intelligence and mechanical engineering. However, there is no real system until now. In our research, its automation methods have developed. Currently, the main themes are: (1) Sketches are often used to draw new ideas such as mechanical parts. We have developed a method to automatically convert them into 3D models. (2) In the civil engineering and construction industry, IT techniques are being promoted, but it is difficult until now. We have developed a system to automatically convert its 2D drawings into 3D models.