Exploring on Evaluation of Human Response to Indoor Daylighting Environment using UE5 Virtual Reality Modelling: A Pilot Study

With advancements in virtual reality (VR) technology, many fields have adopted this technology as an alternative to assess human responses to specific environments without replicating them in the real world. This includes the study of indoor lighting environments. Especially for some advanced window systems still at the lab stage, human perception and acceptance of these innovative window systems, which feature dynamic transmittance and colour tinting, could be evaluated using immersive VR modelling. This can be done before the commercial products are applied, potentially improving indoor daylighting quality and reducing the risk of visual discomfort. However, limited research has validated whether VR technology can accurately reproduce and present a realistic indoor daylighting environment to users, with user feedback closely mirroring that in reality. To address this issue, a pilot randomised crossover study design was implemented to compare and analyse the subjective (e.g., satisfaction level, sense of presence) and objective (task performance) responses of 14 participants in both virtual environments built by Unreal Engine 5 and physical environments in a University library seminar room. The results indicated that 1) no significant differences (p>0.05) in most of the items between the VR and real environments, which means that the participants could achieve a sufficient sense of presence in the virtual environment. 2) Although there were minor items that showed slight deviations and dissatisfaction, these were generally attributed to the relatively low definition and limited resolution of the VR headsets used. Nonetheless, the conclusion can be drawn that the virtual environment can provide an adequate representation of the physical daylit environment, with user responses being reliable. Based on this validation of VR modelling methods, the perception of indoor daylighting with different dynamic smart windows could be further developed in the future.