Our application is a join point model APP. It has three big functions. The first feature is that it is so flexible that you can draw a closed graph on the screen, and then click 3D, and you can generate a 3D model that you can view at any angle. The second function is to open the connection points, and the density of the connection points can drag the progress bar changes. You can fully draw your graphics on this. Compared with the first function, its function is to make you draw the standard graphics better. In the same way, you need to click 3D to generate it. The third function, the 3D button, is used in the first and second functions. And you can choose the section settings on the top right side of the screen. Note: in the use of the application, the user must ensure that a complete picture is drawn, and there can be no lines and patterns inside the graphics. It is necessary to ensure that the inside of the graphics is empty.