Cybersickness & User Comfort - Esin-M/FlUId-VR_UI_Guidelines GitHub Wiki
27. Guidelines to Minimize Simulation Sickness (Adapted from 27(#ref27))
27.1. Design
27.1.1. High latency between user input and visual content causes simulation sickness. 20ms minimum latency is recommended, anything higher than 46ms induces sickness.
27.1.2. Movement should be realistic. Fast falling, rolling, waveform motion, flipping, and rapid zoom should be avoided. Jumping instead of continuous walking can reduce sickness.
27.1.3. Avoid flickers by having a brighter screen and high refresh rate.
27.1.4. Design logical environments. Implement fixed interface elements instead of floating ones, clear reference points, a steady horizon. Avoid imbalanced or changing backgrounds.
27.1.5. A narrower field of view reduces the feeling of movement.
27.1.6. Design for short exposure duration. Allow the user to pause, rest, and continue later.
27.2. User
27.2.1. Focusing on a specific object can reduce sickness.
27.2.2. Prevent symptoms with good airflow and ventilation.
27.2.3. Only engage with the virtual environment when in good health.
28. Cybersickness Reduction Guidelines (Adapted from 28(#ref28))
| Guideline | Description |
|---|---|
| Duration of use | |
| Provide limited time for the duration of use. | It is recommended to take breaks every 15–30 minutes during gameplay. If a user starts to feel symptoms of cybersickness early on, they should stop temporarily before resuming. |
| Provide the notification for resting time. | The app should alert users at regular intervals to take a break, which helps reduce discomfort. |
| Experience | |
| Provide proper exposure for the user before using IVR devices. | Users need to be introduced to IVR equipment, like HMD controllers, and should explore the play area beforehand. |
| Provide simple and understandable instruction or guidelines for the beginner. | Instructions for using IVR should be clear and easy to follow. These should be explained before starting the application. |
| Provide continuous assistance when they are using the IVR devices. | Users should receive ongoing support and guidance while using IVR to help them perform tasks within the virtual environment. |
| Physical Setting | |
| Provide a small screen/viewing area. | A smaller screen works well for showing the virtual environment, especially since HMDs reduce the space of the playing area. |
| Provide a comfortable playing area. | The play space should be arranged so users can move without distraction. This includes proper placement of tracking and computing equipment. |
| A sitting position is suggested. | A seated position is recommended especially for beginners that need to become familiar with the virtual setting. |
| Acceleration Speed | |
| Provide lower or slow acceleration movement. | Slower acceleration in the virtual environment can reduce discomfort, as faster speeds may make some users feel uneasy. |
| Make acceleration short and infrequent. | Acceleration changes should be brief and not often, as too much acceleration can create mismatches in sensory input, leading to discomfort. |
| Provide constant acceleration speed. | Acceleration should stay consistent while the user moves. Sudden changes in speed or direction should be minimized to help the user feel at ease. |
| Allow user to control and initiate acceleration speed. | Users should be able to manage acceleration themselves to avoid sudden movements like jerks or shakes that may be uncomfortable. |
| Movement Speed | |
| Provide constant velocity in character movement. | A stable and consistent movement speed helps users feel more at ease in the virtual world, similar to how they move in real life. |
| Provide realistic body movement. | Adding natural body motions, such as jumping or crouching, enhances realism and can reduce disorientation. |
| Provide adequate visual cues. | Visual indicators are important when teleportation occurs, as they help users stay oriented. |
| Field of View | |
| Change viewing distance. | Users should be able to adjust their field of view (FOV) to maintain comfort. Narrowing the FOV can reduce symptoms, although it may affect the feeling of immersion. |
| Degree of Control | |
| Synchronized camera movement. | Users should be able to initiate camera movement to reduce cybersickness. Sudden shifts in view can cause discomfort. |
| Provide gesture avatar. | Including an avatar helps users anticipate visual motion and enhances the learning experience. |
| Camera | |
| Avoid zooming camera effect. | Zoom effects can cause imbalance and nausea. It's best to remove this feature from IVR applications. |
| Avoid using unnecessary camera templates. | Using unnecessary camera templates can be distracting or confusing. |
| Avoid using the head bobbing effect. | Simulated head bobbing can feel unnatural and may cause discomfort. |
| Head Tracking Viewpoint | |
| Provide responsive user movement display. | The display must always keep up with real-time user movement. |
| Use SDK's position tracking and head model. | Using provided SDKs ensures that the system can track and rotate according to the user's head and body movements. |
| Positional Tracking | |
| Provide a suitable starting position. | Users should begin in a position that aligns with the direction of view and task flow. |
| Limit user area movement/collider component. | Movement in the virtual space should be limited to prevent users from accessing areas unnecessarily, depending on the application type. |
| Provide positional tracking warning signs. | Users should be warned as they approach the boundaries of the tracked space so they can re-position themselves and not lose track. |
| Persistence | |
| Provide persistence movement of 3D model/character and transition of information. | Movement and information transition in the virtual environment should be persistent and consistent to help users stay focused. |
References
27(https://www.researchgate.net/publication/359542855_A_Systematic_Survey_on_Cybersickness_in_Virtual_Environments) A. N. Ramaseri Chandra, F. El Jamiy, and H. Reza, "A Systematic Survey on Cybersickness in Virtual Environments" Computers, vol. 11, no. 4, p. 51, Mar. 2022, doi: 10.3390/computers11040051.
28(https://www.researchgate.net/publication/359106448_A_Comparative_Analysis_on_Cybersickness_Reduction_Guidelines_in_VR_and_IVR_Applications_for_Children_Road_Safety_Education) N. S. Yahaya, A. A. Mutalib, and S. N. Abdul Salam, "A Comparative Analysis on Cybersickness Reduction Guidelines in VR and IVR Applications for Children Road Safety Education" Int. J. Interact. Mob. Technol. IJIM, vol. 16, no. 05, pp. 33–48, Mar. 2022, doi: 10.3991/ijim.v16i05.26359.