Usability of web-based VR - interaction

Beyond navigation, VR applications need to include several options to interact with the virtual environment in an intuitive way, for a high level of immersion. This requires communicating to the user what elements of a scene actually provide corresponding functionalities and which do not. Unfortunately, in many applications this is not represented in an obvious way, forcing the user to move the mouse through the scene and checking where the mouse cursor changes to a cross or pointing hand. As this search is rather soul-destroying, chances are high that most of the laboriously implemented interactive features will never be utilized.

In our applications, we tried to solve this problem by applying two methods of making interactive elements more obvious. One method is to provide an option that highlights these elements, in the example below by dying the corresponding objects. The user can turn this highlighting on and off, if he or she wants to see the scene in its original form.

While technically this option is easy to realize, it is not optimal from a usability perspective, because it remains rather unclear what interactive functionalities will be invoked by clicking on the objects. This aspect could be made salient by providing tooltips, boxes with descriptions that appear when you position the mouse over these objects.

A second option is to represent the interactive functionalities in a toolbar, as shown in the screenshot below. This alternative was selected because a major set of interactivity in the application consists of fading in and out auxiliary geometries, for which the color-coding concept would be an inadequate solution.

Note that the toolbar contains a 'light switch', the rightmost button in the screenshot. Probably you have encountered VR applications in which it is hard to see anything, because of a dim illumination. This problem is due to graphics board differences, which cannot be eliminated by increasing the brightness, because then the view on the VR environment might be better, but the brightness of the surrounding browser and desktop elements would be uncomfortably high. A straightforward solution is to provide controls that allow the user to adjust the illumination of the scene, either in a discrete or continuous way.