CAD (Computer-Aided Design) arbitrary multi-segment line batch rapid splicing method

Abstract

The invention provides a CAD (Computer-Aided Design) arbitrary multi-segment line batch rapid splicing method. The method comprises the following steps: step 1, reading multi-segment lines to be spliced, selecting and reading XY coordinates and Z elevations of vertexes on straight lines, the multi-segment lines, two-dimensional multi-segment lines and three-dimensional multi-segment lines in batch; step 2, checking, deleting duplication and marking the read multi-segment lines; 3, cyclically traversing the head end point and the tail end point of any multi-segment line to be spliced, sequentially searching the head end point and the tail end point of the nearest spliced multi-segment line with the same attribute from the end point Z, and marking the head end point and the tail end point; 4, according to the spliced multi-segment line, the nearest multi-segment line to be spliced and the head and tail end points of the nearest multi-segment line to be spliced, automatically judging whether a sequential or reverse splicing mode is adopted or not, and splicing and marking; and step 5, repeating the steps 3 and 4 in sequence to complete splicing, and drawing the spliced multi-segment lines based on the attributes of the original multi-segment lines. The method is simple in technical principle and easy to operate, has great superiority compared with methods in the prior art, and isworthy of popularization and application in a large number of CAD engineering drawings in the future.

Description

technical field [0001] The invention relates to the field of CAD engineering drawing, in particular to a method for quickly splicing arbitrary multi-segment lines of CAD in batches. Background technique [0002] The field of CAD engineering drawing often involves splicing of a large number of polylines. Especially in the processing of channel bathymetric map or river topographic map data. There are various types of objects such as straight lines, polylines, 2D polylines and 3D polylines in CAD. Among them, the straight line in CAD is the connection between the first and last two endpoints, and there are only the first and last two endpoints; the polyline is the connection between two or more endpoints, which is a whole, and the line segments drawn by the straight line command are all connected to each other. Detached. In addition, there are 2D polylines, 3D polylines, etc. The difference between a two-dimensional polyline and a polyline is that the data of a two-dimensio...

AI Technical Summary

Problems solved by technology

[0003] Because there are many types of CAD polylines, and the data structures are different, although CAD provides polyline splicing commands, there are many problems in the splicing of various polylines: ①The steps of splicing different types of polylines are very cumbersome and complicated , it is very easy to fail the splicing; ② When it contains 3D polylines that are not on the same plane, it cannot be spliced ​​directly; ③ It is impossible to realize the automatic matching splicing of a large number of polylines with different elevations

[0004] In waterway bathymetric maps or river topographic maps, due to various reasons such as drawing software, drawing methods, and post-processing, the drawn contours, contours, or waterlines are often discrete, which brings great difficulties to later extraction and editing. come more difficult

like figure 1 As shown in , many contour lines are interrupted by elevation points, and some contour lines appear to be a continuous line, but are actually interrupted into multiple polylines, making their selection, extraction and editing very difficult

The traditional method is to select objects one by one, which is cumbersome and has a large workload, which is very time-consuming and labor-intensive, and the efficiency is low, and the post-editing still requires a lot of repetitive and tedious work

Especially when a large number of polylines with different Z attributes need to be automatically spliced, traditionally there is no fast and effective method, such as figure 1 There are a large number of discrete isolines with different Z attribute values ​​(elevation values), how to automatically splice polylines with the same Z attribute values ​​at similar distances, the traditional method can only be selected and spliced ​​one by one, which is very time-consuming and labor-intensive. extremely low

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