Web publishing and browsing of 3D graphics in CNC machining
August 14, 2023
Networked CNC machining is facing one of the most basic and most realistic problems. It is web browsing and publishing of product graphics. Through the three-dimensional graphics published on the Internet, users can intuitively browse product design and processing information to facilitate product prediction, product design, product analysis and product processing. However, the graphics published by the Web are generally in the format of a bitmap, so that the 3D graphics displayed on the client is a floor plan, and it is impossible to view the complete product information from different perspectives. In addition, due to limitations of the platforms and software used by developers, the user-downloaded vector graphics cannot be opened properly. Taking the 3D geometric design in CNC machining and the vector graphics of the trajectory simulation as research objects, the 3D graphics publishing and browsing based on Internet sharing technology can be realized, enabling users to browse the 3D graphics published on the Internet on any platform and system. Features such as surface color and texture, and can perform three-dimensional body movement, deformation, translation, rotation and other operations. 1 Web graphics image tr>
Figure 1 Web transfer of graphic images
Figure 2 Web publishing structure graphics for 3D graphics is the first "inline" data type supported by Web browsers. The graphics in the computer can be divided into vector graphics and bitmap images. Figure 1 shows the two types of file format Web transmission. The expression of the vector image is formed by filling the outline. Since the vector image contains various independent image elements, and these elements can be rearranged arbitrarily, the vector image is also called object-oriented graphics. Bitmaps are expressed using the pixels that make up an image or a graphic. A common way to create a bitmap is to use a scanner to scan for photos or images, or you can create software to fill grid cells with different colors. The most commonly used bitmap formats are GIF and JPEG image files. Most browsers provide support for bitmap graphics, so they can be viewed directly on the Web. For the web publishing of vector images, many people currently use lossy compression to convert it into a bitmap format, and then publish it to a local server through the IP protocol and connect to the Intenet. In addition, the virtual reality modeling language VRML may be used to reprogram the vector graphics and use the virtual world scene to express the three-dimensional static graphics. 2 The three-dimensional graphic web publishing structure is based on the graphic image-based web transmission method, and a three-dimensional graphic web publishing structure composition diagram as shown in FIG. 2 is established. The bitmap conversion module performs processing such as scanning and pixel editing on the digitally controlled 3D vector graphics to form a bitmap file having pixel attributes. The vector processing module considers that the user owns and does not own the 3D vector graphics drawing software, and is divided into two processing modes: an isomorphic environment and a heterogeneous environment. In a homogeneous environment, the drawn three-dimensional graphics file is uploaded to the local server together with the bitmap file output from the bitmap conversion module, and the connection with the Internet is realized. The client can directly download the three-dimensional geometric modeling design through the network and enter The self-constructed software environment completes browsing. Heterogeneous environment is more complicated. The function of this module is to enable users to browse the web publishing product graphics without the vector graphics drawing software. In the design of CNC machining, the graphics formed using various drawing software are vector graphics. Bitmaps and vector graphics are used together to complete the Web presentation of three-dimensional graphics in CNC machining. They apply different dry demand conditions. For example, because pixel acquisition and network publishing of bitmaps are quick and easy, they only require photo or graphic scanning or software generation. Although they do not have the multi-view observation feature, they can be used for product introduction, advertising, etc., and involve product design. When the parts information extraction, component assembly and processing and manufacturing, etc., must be a clear and complete presentation of the full-featured parts, you need to publish the product design vector to the network, the user can control the Web browsing components to rotate, pan, zoom , Reduce, and other operations, allowing users to observe product graphic design and processing from different perspectives. 3 Implementation Method Use Pro/E software to perform 3D geometric modeling of product design in milling machining. Then it implements its trajectory display and NC machining simulation. In a homogeneous environment, 3D graphics are hyperlinked to web pages for publishing. Users can download them from the Internet to their own Pro/E environment. Heterogeneous environments need to adopt the following three methods to achieve NC processing under the network environment. Web browsing and publishing of 3D graphics. 3D geometric modeling Web publishing and browsing using VRML format conversion method. VRML is web-oriented, born for the web and developed with the web. It avoids the transmission of an unlimited frame of frame video over the Internet and transmits a limited-capacity WRL file. Use the Pro/E environment to directly export the VRML file of the product geometry and publish and browse it on the web. As shown in Figure 3, the 3D geometric shape of the web page, the components of the web browsing can be rotated, translated, enlarged, and reduced. Web publishing and browsing of knife path In the Pro/E environment, the tool path of the product processing is formed, and then it is converted into a bitmap format. Web insertion and browsing are implemented by using the method of inserting images in the web page. As shown in Fig. 4, the tool path and retract position of the tool relative to the workpiece can be seen. Web publishing and browsing of NC machining simulation adopt screen capture technology to capture the processing simulation of products under Pro/E environment into multimedia avi format, and use Web pages to insert video functions to realize Web publishing and browsing of NC machining simulation. As shown in Figure 5, the dynamic processing of the part can be seen.
Figure 3 3D geometric modeling Web page
Figure 4 Web path of the trajectory
Fig. 5 NC simulation Web page 4 Conclusion The established 3D graphics Web publishing architecture framework is applied to Web page production, and embedded in a homogeneous environment and heterogeneous environment, vector graphics Web browsing methods, have been satisfactory. Using Win98/Win2000 and NT4.0 system platforms, respectively, and in different browsers IE and NetCaptor, have realized the three-dimensional graphical design of CNC machining network browsing and publishing. It has cross-platform and cross-system compatibility.
