Discussion on Pre-printing of Engineering Software

At present, there are two types of engineering design software, Autocad and Ustation. Previously, the main interface for the files created by these two kinds of software was the inkjet output. It is understood that the general export center is still unable to export the software produced by such software to the printing of the film. Sulfuric acid paper must be printed out. In this way, not only the print quality is low, but there is no way to print a color document. This article explores the issues with such files and RIP interfaces.

First, on the issue of AutoCad software

Autocad software is a computer-aided production software that enjoys a global reputation. It is widely used in the design fields of machinery, aerospace, electronics, and communications in China. Its development is mainly used for engineering design and has never been interfaced with printing.

In recent years, many large-scale engineering design drawings need to be printed, so Autocad documents need to be printed out. For this reason, I first thought of two methods for Autocad output characteristics: One is to convert Autocad files directly into Postscript files (this file can be interfaced with any RIP). Later, I discovered that although Autocad files can be converted into Postscript files, the Autocad-defined linetypes, line widths, and fonts are completely different from those defined by the PostScipt language. In this way, the line type, line width, and font are all distorted after conversion. This approach has not been successful.

Another method is to transition the Autocad file into a file of eps, and then place it into PageMaker software so that the film can be output. First of all, we need to select the output printer. Autocad software comes with a wide variety of printers. Based on experience, I chose a Postscript printer. This printer has four more options: 300 dpi; 600 dpi; 1 270 dpi; 2 540 dpi. After the experiment, the 1270 dpi mode was selected. When setting up the printer, everything else should be the default. But when the system asks you "Do you want to change anything"? Select YES at this time. After setting the Size Units, you must enter the file print settings. At this time we must pay attention to the output ratio (according to customer requirements). After setting, special attention should also be paid to setting Pen Assignments (this should be based on the output scale). Otherwise, the output word and line will be deformed. After these options are set, you can output the eps file.

Due to the Autocad software, the output eps file frame often does not come out, or only part of it. I then added a short, thin line around the Cad file (a thin line can be scraped out after the film is removed) so that the file content can be completely exported.

The practice of outputting more than 1,000 geological maps on the hidden works of the Yangtze River dyke shows that this method can output accurate and beautiful films.

Second, the use of fixed-mass output Ustation engineering software

Ustation is the engineering design software recommended by the Ministry of Water Resources and is widely used in the field of hydraulic construction design. There are also software interface issues with this software for prepress. With reference to the successful experience of Autocad Prepress, we first need to convert dwg files to *.000 files. This requires selecting a PostScrip printer, then setting the printer range (using the fence selection) and selecting the desired output file size as needed. This will generate the file. Finally, change the *.000 file suffix to *.eps format, and you can place the page maker in the output format.

However, because Ustation software font data is raster data, the font strokes are composed of small square grids. When the raster data is converted into vector data, some font strokes are automatically incomplete. Over the past few years, our hospital Ustation software output film has such situations in varying degrees. Films need to be manually added after the film is output. This is not only a waste of time, the finished product is not beautiful. Later, I found through years of experience that I first generated the eps file by vectorizing the Ustation file output process, and finally adjusted the scale in Illustrator. This will solve the problem of font stroke incompleteness. However, as the output scale changes, a linear change occurs. Later I opened the printer file and changed the thread width by changing the width of the data in the printer file. This will solve all the problems.

After production practice has proved that this method of proportional transformation basically solves the Ustation production file output film problem.

Wang Changfu, Director, Institute of Surveying and Information Engineering, Changjiang Water Resources Commission