EFFICIENT AND ACCURATE FUSION OF MASSIVE VECTOR DATA ON 3D TERRAIN

Z Liu,Z Zhao,D Zhang,Y Wang,F Wang,C Li

doi:10.5194/isprs-annals-iv-4-119-2018

Abstract

Abstract. This paper presents a viewpoint-related fusion method of massive vector data and 3D terrain, in order to superpose the massive 2D vector data onto the undulating multi-resolution 3D terrain precisely and efficiently. First, the method establishes an adaptive hierarchical grid spatial index for vector data. It will determine the geographic spatial relationship between vector data and the tiles of 3D terrain in the visible area; secondly, this method will use the improved sub-pixel graphics engine AggExt to generate textures for vector data that has been bound to terrain tiles in real time; Finally, considering that a large amount of vector data will generate a lot of 2D textures in the computer memory, the method should release the “expired” vector textures. In this paper, in order to take into account the real-time convergence and the smooth interactivity of 3D scenes, this method will adopt a multi-threading strategy. The experimental results show that this method can realize the real-time and seamless fusion of massive vector objects on the 3D terrain, and has a high rendering frame rate. It can also reduce the aliasing produced by traditional texture-based methods and improve the quality of vector data fusion.

Highlights

In recent years, with the continuous development of computer technology and geographic data acquisition method, and the deepening of GIS applications, more and more people are demanding to deal with problems in real three-dimensional space (Li et al 2011)
The methods for superimposing 2D vector data on the surface of 3D terrain can be roughly divided into three types: geometry-based rendering method, shadow-based rendering method, and texture-based rendering method (Wang et al 2013)
In order to quickly find vector objects that intersect with the tiles of terrain, an adaptive hierarchical grid spatial index must be established for massive vector data (Wang et al 2003)

Summary

INTRODUCTION

With the continuous development of computer technology and geographic data acquisition method, and the deepening of GIS applications, more and more people are demanding to deal with problems in real three-dimensional space (Li et al 2011). With the development of multi-resolution data acquisition technologies such as remote sensing imagery and elevation, the fusion and application of 2D vector data, 3D topographic surface models, and global remote sensing imagery have become a general trend (Kang et al 2009). It is one of the important problems in the field of 3DGIS how to overlay a large amount of 2D vector data on an undulating 3D terrain and ensure real-time, high-efficiency, and high-quality visualization. When faced with massive vector data, most of the methods consume too much time and cannot achieve the purpose of real-time fusion

THE METHOD PROPOSED IN THIS ARTICLE

Establish relationships between 2D vector data and

Draw textures of viewpoint-related vector objects

The textures of vector objects release mechanism

EXPERIMENTS AND ANALYSIS

CONCLUSION