A method and device for generating parallel lines in a road network

Abstract

The invention provides a parallel line generation method and a generation device in a road net. The parallel line generation method includes a first step of aiming at the complex road net, and generating continuous broken lines in each road to avoid a stagger or break-off condition which possibly happens to drawn parallel lines, a second step of taking out and thinning nodes of the broken lines, removing shorter line segments, optimizing quality of the original broken lines, enabling the generated parallel lines to be concise and attractive so as to avoid generation of parts of self-intersecting points at the same time, a third step of solving the problem that intersection points of the line segments are mutually staggered due to inner points of the parallel lines generated according to an angle bisector method, and enabling the line segments to be tidily connected together, and a fourth step of removing the self-intersected inner points, and avoiding the conditions that the generated parallel lines are staggered, broken off or self-intersected. In a word, the parallel lines of each road are generated according to the parallel line generation method, so the method can enable the drawn parallel lines to be reasonable, accurate and attractive.

Description

technical field [0001] The present application relates to the technical field of geographic information systems, in particular to a method for generating parallel lines in a road network and a device for generating parallel lines in a road network. Background technique [0002] The drawing of parallel lines is widely used in geographic information system development, computer graphics, GIS map production, urban planning, underground mining pipelines and mine descriptions. For example, when describing the uplink and downlink of a road, the most intuitive method is to use parallel lines. . [0003] The existing parallel line drawing algorithm is only the extension of the node of the polyline in its normal direction, such as figure 1 As shown, for the known line segment AB, the existing parallel line drawing method is to select a point C to determine the direction, input the distance d between the preset parallel lines, and copy the selected line segment according to the input...

AI Technical Summary

Problems solved by technology

[0012] 2) For the same thread removal, there is a big difference in the drawing effect of the existing algorithm under different scales, as shown in Figure 3 and Figure 4 As shown, ABCD constitutes the original line segment, and A'B'C'D' constitutes the corresponding parallel line, where Figure 3a is the drawing result at a large scale, Figure 3b It is the drawing result at a small scale, and there is a self-intersection point

[0014] 4) For complex road networks, there may be a line composed of several line segments, and the drawn parallel lines may be staggered or disconnected

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