Virtual reality for assessing visual quality and lighting perception: A systematic review

The achievement of a good visual environment is key to guaranteeing human satisfaction indoors. In this context, it is crucial to assess the visual environment through the measurement of human perception. However, the assessment of the visual environment through human perception is often complicated. Using real spaces or mock-ups is time consuming, costly, and does not allow the control of all possible variables (e.g., daylight). Photorealistic rendered images present several limitations, starting from the veracity of the visual stimulus presented to participants. Virtual Reality (VR) is emerging as a valid alternative for evaluating the perception of the indoor visual environment due to the ability to control selected variables, analyse cause-effect relationships, and save time and cost, especially for the evaluation of daylit spaces. The high level of immersion and the possibility of interaction provide an opportunity to study users' perceptions and behaviors. However, some aspects of light assessment in VR need further investigations, such as the comparability of the perception of light in real and virtual environments. This paper reviews the available literature on the topic, highlighting the advantages and disadvantages related to the use of VR for lighting research and design. Previous research is classified into 1) studies focused on the comparability between lighting conditions in VR and real environments; 2) studies about users’ perception and behavior with respect to lighting scenarios in VR; and 3) studies exploiting VR for lighting design. Hardware and software used in existing literature are further analyzed. This paper highlights that more studies are needed to define a common investigation protocol to make VR a valid investigation tool for lighting research studies aimed at evaluating visual quality and lighting perception.