The display should respond to the user’s movements at all times. Constant velocity and reducing the need for rapid movement, strafing, back-stepping, and spinning further helps prevent simulator sickness.
Objects should be rendered a comfortable distance away from the user. Bright scenes or abrupt transitions should be kept to a minimum to avoid simulator fatigue. Some users may find environmental setups discomforting, such as height, small spaces or colliding objects.
Interactive objects should be placed well within reach and appropriately scaled. Relevant UI elements should be narrowed to fit within the user’s field of view and be placed on slightly curved concave surfaces. Physiological differences may require adjustments for height and disabilities.
Familiarity and the concept of affordance can help bridge the gap between the real and the digital. Virtual hand movements and positions should match real-world settings.
A static reference frame, such as fixed objects or a texturized floor, will help keep the user grounded. An unstable horizon line or other visuals that upset the user’s sense of stability should be avoided.
Users should always stay in control of their movements and every interactive element should be reactive. Reticles, cursors or crosshair that are rendered in 3D space can help the user stay in control when selecting objects.
Interactions should be natural and intuitive, and physical designs should afford particular uses. Interactive elements should clearly communicate their potential and active states.
Directional audio can draw a user’s attention towards specific areas. Virtual eye contact can help focus on a character.
Instructions should be brief and can be displayed with overlaying text based prompts or audio summaries.
Lit or unlit areas can provide information about where users are able to go or what they're able to do next. A user’s gaze can trigger the appearance of relevant information.
Feedback is important to guide the user to make the right actions, and avoid errors. Sound effects and haptic feedback make the experience more tangible.
Spacial audio will make the application more realistic. Individual feelings and emotional reactions to moods, interactions or relationships help intensify the sense of presence.
Break free from traditional 2D designs and implement interfaces into the 3D space. Interactions in VR should be similar to interactions in reality. Beautiful and abstract designs help to forgive inconsistencies. Perspective and scale can be used to your advantage. Additional depth cues, such as blurring or parallax, reinforce the sense of depth.
It is about an experience that needs to be looked at in its entirety. Users can look in any direction at any time, their intentions should always be understood. Virtual worlds offer the potential for extending human abilities or creating unique personal and social experiences.