Comparison method and device for computer aided design drawings

Abstract

The invention relates to a comparison method and device for computer aided design drawings. The method comprises the steps of reading to-be-compared design drawing files to acquire to-be-compared design drawing data; analyzing the to-be-compared design drawing data to obtain all primitive information contained in the design drawing data; according to all primitive information contained in the to-be-compared design drawing data, dispersing the primitives into primitive pixel data corresponding to the screen display effect in sequence, and combining the primitives into drawing pixel data corresponding to the to-be-compared design drawing data; and comparing the obtained drawing pixel data to obtain the difference between the to-be-compared design drawing data. Based on pixel comparison, GPUor parallel processing mode acceleration can be adopted, rapid and accurate comparison between drawings with very high complexity and very large modification amount can be achieved, and rapid and accurate comparison between dissimilar design drawing files can also be achieved.

Description

technical field [0001] The present invention relates to a file data comparison technology, in particular to a comparison technology for effectively identifying differences in computer-aided design drawings, in particular to a method for comparing differences in engineering design drawings generated by CAD design software such as AutoCAD, CATIA, and SolidWorks, and to realize the method The device and system of the method also involve comparing file data differences and visual differences of engineering design drawings by means of pixel comparison. Background technique [0002] CAD drawings are the main way for design companies to express design ideas and communicate with construction companies, so they are widely used in various industries such as architectural design and machinery manufacturing. The management of design drawings is a major challenge faced by these industries. The difficulty lies not only in the large number of various design drawings, but also in the large ...

AI Technical Summary

Problems solved by technology

In these many links, the wrong version of design drawings may be used at any time due to the failure to accurately identify the differences between different versions of design drawings, resulting in losses of varying degrees; It is also often difficult for users to quickly and accurately obtain the differences between different drawings, so related industries urgently need technologies that can help users quickly and accurately obtain the differences between different drawings

[0003] For design drawing comparison technology, the difficulty is much higher than that of common text comparison, because the graphic elements in the design drawing are distributed in two-dimensional or even three-dimensional space, and it is difficult to show the difference; and the appearance attributes of the graphic elements are various, The criteria for judging similarities and differences are also complex

Some existing design drawing comparison tools can clearly tell the user the difference between the two drawings by comparing the appearance and detail attributes of the graphic elements in the design drawing. These tools are all for the DWG file format of AutoCAD, that is The similarities and differences of the two drawings are copied to another drawing, and then displayed by changing the color, so there are the following problems: first, only scattered elements can be compared, and blocks and reference files cannot be compared; second, only It can perform pair comparison according to the handle (handle, that is, the unique identification of the primitive in the drawing), that is, the comparison of these tools is based on the premise that the two drawings are modified from the same drawing.

However, this method not only compares the primitives through the same handle, but also compares the space number and primitive attributes. When the complexity of the drawing is high or the modification content is large, the computational complexity increases geometrically, and it can only Realize the comparison of AutoCAD DWG files, or the comparison of the same kind of design drawing files, but cannot realize the comparison of heterogeneous design drawing files, that is, because the definitions of graphics elements and their attributes are not exactly the same between different CAD software, even AutoCAD The definition of element properties is not exactly the same between different versions, so this method cannot accurately identify the differences in the design drawing files

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