How Much Is Too Much? Comfort Envelopes for Distortions in Virtual Reality Interaction

Virtual reality (VR) is compelling precisely because it transcends physical realism, allowing reach to be stretched, motion rescaled, and objects relocated. While these distortions expand interaction possibilities, they lack principled limits: How far can they go before agency, ownership, or presence collapse? We present a dual-axis framework that decomposes distortions into metric deviations (continuous remappings akin to stretching) and topological breaks (discontinuous jumps akin to cutting), both applied to the same hand-target relation. To operationalize this framework, we introduce the Single-Interaction Dual-Axis (SIDA) protocol, combining a standardized task with psychophysical estimation of Just-Acceptable Distortion (JAD) and Breaks in Presence (BiP) under stable or jittered mappings. In a study with $N=52$, results show that metric deviations are significantly more tolerable than topological breaks, predictability expands tolerance by approximately 35%, and combined distortions interact contractively, constraining the total budget. Our contributions include (i) a unified model for commensurate comparison, (ii) a reproducible protocol for threshold estimation, and (iii) the comfort envelope, a multi-dimensional budget of acceptable distortion that guides trade-offs between agency and presence in VR design.