Which 3D label effect works better? Usability analysis using eye-tracking

Three-dimensional (3D) maps, with their volumetric features and depth information, can effectively enhance user’s spatial understanding and perception of geographical environments. The integration of various 3D label effects enriches the expression of geographic information and improves map usability. However, the usability of these label effects still lacks systematic investigation, and in current practice, users often rely on personal preferences or system defaults when making choices. This study employs eye-tracking experiments and surveys to evaluate the usability of five different label effects – standard, glowing, color-changing, transparent, and billboard – within 3D static maps from the perspectives of screen space (SS) and world-space (WS). The findings reveal that labels in screen space labels are particularly effective for search tasks, while labels in world space labels provide strong visual cues that enhance associations with reference features. Notably, the billboard label exhibited higher cognitive efficiency and effectiveness in map tasks, whereas the transparent and glowing labels showed relatively lower cognitive efficiency and accuracy. However, in terms of cognitive load, the billboard label demonstrated a higher cognitive load, while the color-changing label was associated with a lower cognitive load. The strategic selection of appropriate labels not only improves the readability of map objects but also enhances overall map comprehension and task performance in 3D scenes.