“…Proposed by Benedikt (1979), the isovist is among the earlier attempts in this regard, and it is expressed as the volume of visible space from a given vantage point. The advancement of computational techniques has allowed for the further expansion and development of these methods, which include visibility graph (Batty, 2001; Turner, 2001), the Spatial Openness Index (Fisher-Gewirtzman & Wagner, 2003, 2006; Fisher-Gewirtzman, 2017), and Visual Impact Volumetric Analysis (Lin et al, 2020). As one type of visibility graph, viewshed analysis is still among the most popular geographic information system (GIS) tools employed in visibility assessment (Karimimoshaver and Winkemann, 2018; Turner, et al, 2001; Danese et al, 2009; Rød and Van der Meer, 2009; Van der Hoeven and Nijhuis, 2012); nevertheless, it has many limitations when applied to the visual impact assessment of a single building from a human perspective (Nutsford et al, 2015).…”