  Remote sighted assistance (RSA) has emerged as a conversational assistive
technology, where remote sighted workers, i.e., agents, provide real-time
assistance to users with vision impairments via video-chat-like communication.
Researchers found that agents' lack of environmental knowledge, the difficulty
of orienting users in their surroundings, and the inability to estimate
distances from users' camera feeds are key challenges to sighted agents. To
address these challenges, researchers have suggested assisting agents with
computer vision technologies, especially 3D reconstruction. This paper presents
a high-fidelity prototype of such an RSA, where agents use interactive 3D maps
with localization capability. We conducted a walkthrough study with thirteen
agents and one user with simulated vision impairment using this prototype. The
study revealed that, compared to baseline RSA, the agents were significantly
faster in providing navigational assistance to users, and their mental workload
was significantly reduced -- all indicate the feasibility and prospect of 3D
maps in RSA.
