Locomotion comfort and usability

• Control duration and frequency: By keeping accelerations brief and infrequent, the likelihood of discomfort reduces. This approach leverages the delay before the mismatch between vision and vestibular cues causes unease.
• Implement quantized velocity: This method involves setting fixed movement speeds (for example, stopped, walking, running) and switching between them instantly. This reduces the duration of perceived acceleration, minimizing the mismatch between what users see and feel.
• Use stepped translations: Instead of smooth motion, implement movement as a series of small, rapid teleports. This technique, similar to snap turns in rotation, helps eliminate the perception of continuous motion, thereby reducing vection and potential discomfort.
• Restrict movement axes: Limiting movement to certain axes or specific angles (like 15, 30, 45, 90, or 180 degrees) can prevent disorientation, especially in sensitive users. The most restrictive form involves allowing only forward and backward movement, requiring users to physically turn to change direction, which aligns visual and vestibular inputs more closely.
• Stabilize camera elevation: To avoid the discomfort caused by vertical movements over uneven terrain, adjust the camera to maintain a consistent elevation relative to the ground. This can be achieved by repositioning the camera only when necessary, using techniques like teleportation or gradual elevation changes to smooth out transitions.
• Soft camera collisions: When the camera collides with virtual objects, opt for a soft collision approach where the camera slows down before stopping, rather than an abrupt halt. This method reduces the shock of sudden stops and helps users anticipate and adapt to boundaries more naturally.

• Realistic Movement Speeds: Set avatar walking and running speeds to match real-world rates (walking ~3 mph/1.4 m/s, running ~6 mph/2.8 m/s) to avoid excessive optic flow.
• Vignettes: Use vignettes to darken or occlude screen edges during movement, limiting visible optic flow. Advanced vignettes can selectively block areas with the most motion cues, balancing comfort and immersion.
• Occlusion of Surroundings: Incorporate geometry like vehicle cabins, cockpits, or headgear to naturally obscure parts of the environment, reducing optic flow while maintaining immersion.
• Temporal Occlusion: Briefly obscure parts of the display during rapid movement (For example: dynamic edge patterns or color ribbons) to minimize optic flow without disrupting environmental awareness.
• Peripheral Vision Occlusion: Make geometry opaque in peripheral areas to hide detailed environments and reduce optic flow, especially effective in vehicles with windows showing outside motion.
• Reduced Texture Detail: Use solid textures and minimize visible edges or noise in art style. Consider dynamic techniques that lower texture detail based on movement speed to further reduce optic flow.

• Virtual environments
• Locomotion types
• User preferences
• Input maps
• Best practices