Evaluating an Immersive Space-Time Cube Geovisualization for Intuitive Trajectory Data Exploration

Abstract

Fig. 1. Our immersive space-time cube (STC) aims to lower the known steep learning curve of this three-dimensional spatio-temporal representation. The base map is coupled to a virtual reproduction of the analyst's own real desk and all data manipulations and queries are implemented through intuitive gestures and tangible controls, increasing usability and comfort, while decreasing mental workload.Abstract-A Space-Time Cube enables analysts to clearly observe spatio-temporal features in movement trajectory datasets in geovisualization. However, its general usability is impacted by a lack of depth cues, a reported steep learning curve, and the requirement for efficient 3D navigation. In this work, we investigate a Space-Time Cube in the Immersive Analytics domain. Based on a review of previous work and selecting an appropriate exploration metaphor, we built a prototype environment where the cube is coupled to a virtual representation of the analyst's real desk, and zooming and panning in space and time are intuitively controlled using mid-air gestures. We compared our immersive environment to a desktop-based implementation in a user study with 20 participants across 7 tasks of varying difficulty, which targeted different user interface features. To investigate how performance is affected in the presence of clutter, we explored two scenarios with different numbers of trajectories. While the quantitative performance was similar for the majority of tasks, large differences appear when we analyze the patterns of interaction and consider subjective metrics. The immersive version of the Space-Time Cube received higher usability scores, much higher user preference, and was rated to have a lower mental workload, without causing participants discomfort in 25-minute-long VR sessions.

Exploring Multiple and Coordinated Views for Multilayered Geospatial Data in Virtual Reality

“…Scanning through a stack also requires eye movement in one direction only-all representations of an area are aligned vertically, as opposed to being spread out in the two dimensions of a grid. Additionally, the way that the individual maps are arranged in the stack mirrors the way maps are traditionally, and still today, often viewed in professional settings: as a flat print or display on a table, inclined to the viewer-even in VR applications [27]. All of the maps share the same relative inclination and distance to the viewer, as well as the same visual distance to each other, avoiding occlusion (all of which is constantly being adjusted by tracking the HMD's position), and thus the same perspective distortion, making them easier to compare visually [37].…”

“…The emerging field of immersive analytics [21] aims to combine the advances of immersive technologies with visual analytics [22] and has already resulted in applications for large-scale geospatial visualizations-world maps of different shapes [23], global trajectories [24], and even complex flight paths [25]. However, urban environments have so far mostly been immersively explored only in 3D city models [26], or by adding data to one spatial layer [27]. Most recently, different spatial arrangements of small multiples for spatial and abstract data have been investigated in VR [28].…”

Exploration of Time-Oriented Data in Immersive Virtual Reality Using a 3D Radar Chart Approach

“…Approaches to visualize and explore data originated on social networks using immersive technologies exist [4,21,29], providing insights into real world application use cases and potential benefits, such as supporting user focus and attention, creating affective personal experiences, and facilitating data understanding and representation. The results of a study conducted by Wagner Filho et al [41] point towards higher usability, higher user preference, and lower mental workload when using immersive display technologies over traditional non-immersive 2D displays in a scenario that featured the exploration of spatio-temporal data in 3D, thus presenting further indications towards the suitability of applying immersive technologies within the context of 3D data visualization. Studies that focus on the investigation of the user experience and interaction design, such as the ones presented by Cordeil et al [12], Streppel et al [38], Huang et al [20], and Reski and Alissandrakis [35], are equally important as they provide recommendations and guidelines in regard to the choice of display and input technologies as well as different interaction techniques in order to actively interact with data in immersive environments.…”

Personal Augmented Reality for Information Visualization on Large Interactive Displays

“…AR visualizations are directly situated on the display and analysts interact with proxies on the interactive surface. Furthermore, work that shows display-like surfaces in a pure VR environment [30,31,69] may be adapted to a setup consisting of a physical display and head-mounted AR.…”