“…Here, SVGD includes two additional constraints: i) Personal preference constraint θ, which requires that for a user u, any user v rendered in u's VR display must have a personal preference at least θ, i.e., p(u, v) ≥ θ, ∀u ∈ V, v ∈ A u . Following (Hsu, Shen, and Chang 2020;Hsu, Lan, and Shen 2018), the above constraint aims to meet the minimum required personal preferences to prevent users from becoming extremely dissatisfied. In SVGD, this personal preference constraint (referred to as preference constraint hereafter) avoids rendering users that receive a low personal preference; ii) Display slot k u for all u ∈ V , which specifies the maximum number of other users that can be rendered on user u's VR display, to prevent too many people being rendered on users' VR displays, making the displays too crowded 1 .…”