BqR-Tree: A Data Structure for Flights and Walkthroughs in Urban Scenes with Mobile Elements

• Published in: Computer graphics forum Vol. 29; no. 6; pp. 1745 - 1755
• Main Authors: Pina, J.L., Seron, F., Cerezo, E.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.09.2010
• Subjects: Blocking; Computer based modeling; Computer graphics; Data structures; dynamic urban scenes; Dynamics; I.3.6 [Computer Graphics]: Graphics data structures and data types; Origins; Partitioning; Partitions; Quadtrees; Rendering; Studies; Urban areas; view culling; virtual flights and walkthroughs; Virtual reality; Visualization
• ISSN: 0167-7055; 1467-8659
• DOI: 10.1111/j.1467-8659.2010.01654.x

BqR‐Tree, the data structure presented in this paper is an improved R‐Tree data structure based on a quadtree spatial partitioning which improves the rendering speed of the usual R‐trees when view‐culling is implemented, especially in urban scenes. The city is split by means of a spatial quadtree partition and the block is adopted as the basic urban unit. One advantage of blocks is that they can be easily identified in any urban environment, regardless of the origins and structure of the input data. The aim of the structure is to accelerate the visualization of complex scenes containing not only static but dynamic elements. The usefulness of the structure has been tested with low structured data, which makes its application appropriate to almost all city data. The results of the tests show that when using the BqR‐Tree structure to perform walkthroughs and flights, rendering times vastly improve in comparison to the data structures which have yielded best results to date, with average improvements of around 30%.