Head tracking enables objects in virtual space to maintain fixed positions regardless of how you move your head, creating the perception of a virtual world surrounding you.
The most important guideline in designing for virtual reality is to always maintain head tracking. Never stop tracking the user’s head position inside of the application. Even a short pause in head tracking will cause some users to feel ill.
Render 2D splash screens in 3D space
Fixing the splash screen, or any graphic, to the user’s head and turning off head tracking may cause discomfort.
When displaying a splash screen, with a logo or title sequence, render 2D sprites in a 3D virtual space and maintain head tracking. VR applications using splash screens that only track head rotation to one degree of freedom (1DOF) can avoid nausea for most users, but 3DOF (rotation, pitch, and yaw) is still preferable.
Avoid slight freezes in head tracking
When testing your app, pay close attention to when head tracking freezes unintentionally. These moments may occur when loading a new scene or pushing the capabilities of the device. If your app consistently drops head tracking at a particular time, fade the screen to black prior to losing tracking.
What if you can’t have head tracking turned on?
Maintaining audio feedback when the screen fades to black will help establish that the app is still running, and indicate it is loading new information.
Filling the entire screen with a changing color or brightness level can provide visual feedback without the disorientation of turning off tracking. This is because the screen is changing as a whole, and there aren’t distinct objects that fail to track.