In my recent VRDC talk I spent a slide talking about limitations of the platform. The most common complaint about HoloLens and just about any other AR or MR platform is the small window in which the augmentations appear. This low FOV issue is a huge problem of physics that’s not likely to be solved according to Moore’s Law. Get used to it. We’re going to be stuck with it for awhile. (Please someone prove me wrong!)
It’s not the end of the world. It’s just that developers have to learn how to build applications around this limitation.
GUIDE THE USER
Most VR applications require the user to look around. After all, that’s the whole point of being immersed in a virtual environment. Even if it’s a seated experience, usually the player is encouraged to search the scene for things to look at or interact with.
In mixed reality, the lack of peripheral vision (or anything near it) due to FOV limitations makes visually searching for objects frustrating. A quick scan of the scene won’t catch your eye on something interesting, you have to look more deliberately for stuff in the scene.
Perhaps a more natural version of this is used in Young Conker. The directional indicator is 3D, naturally sliding along and colliding with the environment.
USE AUDIO CUES
Unity makes it incredibly easy to add spatial sound to a HoloLens app. Simply enable the Microsoft HRTF Spatializer plugin in the audio settings and check off “spatialize” on your positional audio sources. This is more than just a technique for immersion–the positional audio is so convincing you can use it to direct the user’s attention anywhere in the environment. If the object is way out of the user’s view, emit a sound from it to encourage the player to look at it.
DESIGN ART ACCORDINGLY
Having art break the limited FOV frame is a real problem. To a certain degree, this can’t be solved–get close enough to anything and it will be big enough to go beyond the FOV’s augmentation area.
This is why I design most HoloLens games to work with lots of smaller models instead of large game characters or objects. If the thing of interest to the user isn’t breaking the frame, he might not notice the rest of the graphics are getting clipped. Also, Microsoft recommends keeping the clipping plane a few feet out from the user–so if you can design the game such that the player isn’t supposed to get close enough to the holograms, you might be able to prevent most frame-breaking cases.
For AR/MR developers, limited FOV is a fact of life. In enterprise apps where you are focused on a specific task, it’s not so bad. For games, most average players will be put off if they have to wrestle too much with this limitation. Microsoft’s showcase games still play very well with this restriction, and show some creative ways to get around it.