Evaluating and visualizing perceptual impressions of daylighting in immersive virtual environments

This paper proposes a gamified approach to collect and visualize human perception of daylighting in large-scale indoor environments using immersive virtual environments (IVEs). The developed system was tested by 20 participants, where their daylighting preferences for the virtual environment were collected at two daytimes through snapshotting and evaluating their points of interest in terms of brightness, as well as their evaluation of the system and daylight quality. Afterward, participants’ feedback was visualized into a perceptive lighting map (PLM) and compared to an image-based quantitative metric. The results of this experimental study found a tendency among participants to report more feedback in areas with large daylight portals rather than other areas with similar light intensity. Additionally, results from both subjective and simulation-based metrics showed consistency in defining daylight intensity, as well as explained the occurrence of contradicting user evaluations of some identical areas in IVE as a result of high contrast in brightness. The findings showed the adequacy of the proposed system as a visual source of user-centered feedback to daylighting in the early stages of design, as well as a supplement tool for building performance simulations (BPS)

Room-Temperature Plastic Deformation of Strontium Titanate Crystals Grown from Different Chemical Compositions

Oxide materials have the potential to exhibit superior mechanical properties in terms of high yield point, high melting point, and high chemical stability. Despite this, they are not widely used as a structural material due to their brittle nature. However, this study shows enhanced room-temperature plasticity of strontium titanate (SrTiO3) crystals through the control of the chemical composition. It is shown that the deformation behavior of SrTiO3 crystals at room temperature depends on the Sr/Ti ratio. It was found that flow stresses in deforming SrTiO3 crystals grown from a powder with the particular ratio of Sr/Ti = 1.04 are almost independent of the strain rate because of the high mobility of dislocations in such crystals. As a result, the SrTiO3 crystals can deform by dislocation slip up to a strain of more than 10%, even at a very high strain rate of 10% per second. It is thus demonstrated that SrTiO3 crystals can exhibit excellent plasticity when chemical composition in the crystal is properly controlled

Visualizing user perception of daylighting: a comparison between VR and reality

This study introduces a novel method to investigate human perception of daylight in an interactive and immersive way, using game-engine and virtual reality (VR). The proposed method produces highly realistic renderings in real time of which users can explore freely and report daylight brightness perception using rated snapshots. Perceptions on daylighting in the virtual environment were found consistent with that in the physical one. The proposed approach can overcome some of the challenges facing current light simulation tools, regarding rendering speed and interactivity. It also encourages more validation studies to light simulation in game-engines

Visualizing user perception of daylighting: a comparison between VR and reality

This study introduces a novel method to investigate human perception of daylight in an interactive and immersive way, using game-engine and virtual reality (VR). The proposed method produces highly realistic renderings in real time of which users can explore freely and report daylight brightness perception using rated snapshots. Perceptions on daylighting in the virtual environment were found consistent with that in the physical one. The proposed approach can overcome some of the challenges facing current light simulation tools, regarding rendering speed and interactivity. It also encourages more validation studies to light simulation in game-engines.publishedVersio