This study investigated to what extent people can develop global spatial representations of a multiroom environment through one-shot physical walking between rooms. In Experiment 1, the participants learned objects' locations in one room of an immersive virtual environment. They were blindfolded and led to walk to a testing position either within the same room (within-boundary) or in an adjacent novel room (across-boundary). They conducted judgments of relative direction (JRD) based on the remembered locations of objects. The participants' actual perspectives and imagined perspectives of JRD trials were manipulated to be aligned or misaligned (i.e., faced the same or opposite cardinal directions). The results showed better JRD performances for the aligned perspectives than the misaligned perspectives in the across-boundary condition; this global sensorimotor alignment effect was comparable with the effect in the within-boundary condition. Experiments 2-6 further examined global sensorimotor alignment effects after across-boundary walking. Experiments 2-3 manipulated factors related to encoding global relations (i.e., explicit instructions to attend to walking and keep track of spatial relations, and visual cues for navigational affordance to another space). Experiments 4-6 manipulated factors related to retrieving global relations in JRD (i.e., learning orientation as one imagined perspective, learning position and orientation as the imagined viewpoint, and the number of imagined perspectives). The results showed robust global sensorimotor alignment effects in all experiments, indicating that the participants updated actual headings relative to remembered objects in the other room. Global spatial updating might be the primary mechanism for developing global spatial representations of a multiscale environment.