Method and device for overlaying vector elements and digital ground model

Abstract

The embodiment of the present invention discloses a method and device for superimposing vector elements and digital ground models, which can obtain at least one discrete point on the vector elements that can represent the outline of the vector elements; in the digital ground model, find the corresponding two-dimensional plane coordinates of the discrete points Elevation value; establish the relationship between the two-dimensional plane coordinates of discrete points and the elevation values ​​corresponding to the two-dimensional plane coordinates. It can be determined through experiments that the method and device for superimposing vector elements and digital ground models provided by the embodiments of the present invention have tight joints when superimposing vector elements and digital ground models, without losing the appearance characteristics of the real terrain. Compared with the intersection algorithm, the calculation is more concise, It is not easy to produce errors. Compared with texture algorithms, it will not generate large texture overhead, and realizes reducing the probability of cracks between vector elements and digital ground models on the basis of occupying a small memory space.

Description

technical field [0001] The invention relates to the technical field of electronic maps, in particular to a method and device for superimposing vector elements and digital ground models. Background technique [0002] Vector elements and digital terrain model (Digital Terrain Model, DTM) are important components of electronic map data. Among them, the vector element is two-dimensional data (only including x, y plane information), while the digital ground model is three-dimensional data, which includes both x, y plane information and z elevation information. When drawing electronic maps, overlaying vector elements with digital ground models can greatly improve map rendering efficiency. [0003] At present, there are two commonly used methods for overlaying vector elements and digital ground models. One is the intersection algorithm. Make a vertical line downward, and the z value (ie, the elevation value) of the intersection point of the vertical line and the digital ground mo...

AI Technical Summary

Problems solved by technology

[0004] However, the inventor found in the process of realizing the present invention that when the vector element and the digital ground model are superimposed by the intersection algorithm, it is easy to cause cracks between the vector element and the digital ground model, and the rendering effect is poor; while the texture method does not There will be cracks between the superimposed vector elements and the digital ground model, but the texture method will generate a large amount of texture data during the superposition process, and these texture data occupy a large amount of memory space

Images