Continuous locomotion keeps spatial sense but readily causes discomfort

What it is

Push the stick forward and ground texture starts to stream; corridor corners arrive gradually, not as a cut. Continuous locomotion crosses space with unbroken virtual translation. Surfaces on the path enter the view in order, so spatial updating can integrate along the route. The same optic flow also tells the vestibular system “you are accelerating” while the body is not.

What it keeps is spatial continuity along the way. What it pays is visual–vestibular conflict. Both are bound to the same motion; one cannot be taken without the other.

Why it happens

Spatial updating wants continuous change: optic flow writes passed walls, doors, and turns onto a single trajectory, so a person can point at “that door, back and to the left” without waiting for a new snapshot. The cost is a sustained self-motion signal on the peripheral retina. Otoliths sense acceleration and canals sense head rotation; both sit near zero while a seated user pushes a stick, and vision reports speed. Conflict intensity scales with flow area and speed, but whether conflict exists at all depends on there being this pretend-walking flow, not on how violent any one acceleration spike is.

Continuous locomotion and discrete jumps are therefore a symmetric swap: the jump deletes flow, spares the stomach, and drops along-route integration; sliding keeps the flow, keeps the integration, and exposes the stomach. Choosing a locomotion technique is choosing which ledger to pay.

Studying it

On one route that requires turns and a return, compare continuous translation with discrete jumps. On the spatial side: blind pointing, scene recognition, walking the path back. On the discomfort side: in-session FMS and a post-session SSQ. The two curves usually run opposite: spatial scores favour continuous, sickness scores punish it.

SSQ alone will convict continuous locomotion as the worse scheme. Pointing error alone will crown it the better one. Collect both, and write down session length — people who are fine at ten minutes may drop out at thirty.

Where it stops holding

When real walking already supplies the virtual translation, continuous locomotion adds no extra conflict, and gait has already paid the spatial benefit. Seated use, a narrow tracking volume, and long sessions let the conflict side dominate the choice. Players highly adapted to smooth motion can suppress sickness while the spatial benefit remains. On 3DoF headsets translation is fake to begin with: integration still happens, and the conflict is harder. Content with almost no along-route structure to remember — a straight conveyor-belt level — yields near-zero spatial gain and only the discomfort.

Applying it

• When the scene depends on route memory, relative heading, or finding things along the way, offer continuous locomotion rather than teleport alone.
• Ship a disableable comfort alternative so people for whom discomfort wins can leave continuous translation without leaving the experience.
• Set the default speed in a range where along-route surfaces remain readable. Do not use speed to compensate for an oversized level.
• How to check: walk the same three rooms that must be passed in order, once continuous and once teleport. Continuous should support pointing at the just-passed room’s side; if pointing is right but FMS is already near dropout, the spatial gain is being eaten by discomfort — ship a switch, do not make continuous the only path.

Related

• Same group: N4.02.2 Acceleration and turning are the strongest sources of discomfort · N4.02.3 Constant-speed straight motion is less uncomfortable than speed change
• Nearby: N4.07 Continuous Locomotion and Discomfort · N4.03 Cybersickness Mitigation
• Search terms: continuous locomotion · steering locomotion · path integration