A building label placement method for 3D visualizations based on candidate label evaluation and selection

ABSTRACT

Adding building labels greatly improves the recognizability of buildings and the readability of three-dimensional (3D) city scenes. However, building label placement is much more complex in 3D scenes than in two-dimensional (2D) maps. The annotation effect is influenced by the attributes of the 3D label, building visibility, and the spatial relationship between the building and viewpoint. In this context, automatically generating building labels for 3D scenes during interactions requires highly complex computations. By contrast, evaluating candidate labels and then selecting the suitable label for each building can be effectively implemented. This paper introduces an approach for labeling buildings in 3D scenes based on evaluations of label candidates. The proposed method predefines a candidate label set for each building. These candidates are then evaluated in terms of their attributes and the relationship between the labels and viewpoint at runtime. The best candidate label, or a situational alternative for each building, is then placed in order of comprehensive label priority to avoid annotation conflicts. A series of experiments demonstrate that this method effectively enhances the correlation of labels and buildings, improves interactive efficiency, and realizes a viable global label layout.

KEYWORDS:

• 3D visualization
• building label
• conflict graph
• label evaluation
• label priority

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under Grant number 41871293 and Grant number 41371365.

Notes on contributors

Jiangfeng She

Jiangfeng She is an associate professor at Department of Geographic Information Science, School of Geography and Ocean Science, Nanjing University. His research interests include spatio-temporal data model, virtual geographic environments, computer graphics, geographical information system and related applications in urban planning, construction, land resource management and water engineering projects.

Xinchi Li

Xinchi Li is a graduate student at Department of Geographic Information Science, Nanjing University. His research topics include virtual geographic environments, cartography, and computer graphics.

Junyan Liu

Junyan Liu is a graduate student at Department of Geographic Information Science, Nanjing University. Her research interests are virtual geographic environments and 3D terrain reconstruction.

Yaqian Chen

Yaqian Chen is a graduate student at Department of Geographic Information Science, Nanjing University. Her research interests are spatial data analysis and 3D cost distance.

Junzhong Tan

Junzhong Tan is an associate professor at Department of Geographic Information Science, Nanjing University. His research interests include Web-GIS, virtual geographic environments and spatio-temporal data analysis.

Guoping Wu

Guoping Wu is an associate professor at Department of Geographic Information Science, Nanjing University. His research interests include digital earth, physical geography, geographic modeling and GIS application.