Clear vs. overcast: Effects of sky condition on daylit view perception in virtual reality

• Daylight fluctuations influence views-out perception and physiological responses. • Overcast conditions significantly lower view ratings compared to clear skies. • Sky conditions influence perception but have minimal impact on visual engagement. • Higher impression ratings are associated with increased visual attention metrics. This study investigates how changing sky conditions in window views influence visual perception in a virtual reality environment. Over two experimental sessions, participants viewed 10 distinct window scenes, each recorded as real-time videos under clear and overcast sky conditions. Perceptual impressions were assessed using numerical ratings, verbal feedback, physiological measures, and eye-tracking data. Our findings reveal two key outcomes: (1) clear sky conditions significantly enhanced impression ratings, particularly for scenes that were initially rated as less preferred; (2) for lower-rated scenes, an increase in skin temperature was observed, indicating heightened physiological arousal. However, fixation count and duration did not show significant changes in this category. Instead, fixation metrics increased across rating groups, suggesting a strong association between higher impression ratings and greater visual engagement. These results highlight the importance of incorporating dynamic daylight conditions in view perception studies and emphasize the need for diverse sky representations in VR-based environmental research.