HoloLens lets you create holograms, objects made of light and sound that appear in the world around you, just as if they are real objects. Holograms respond to your gaze, gestures and voice commands, and can interact with real-world surfaces around you. With holograms, you can create digital objects that are part of your world.
The holograms that HoloLens renders appear in the holographic frame directly in front of the user's eyes. Holograms add light to your world, which means that you see both the light from the display and the light from your surroundings. HoloLens doesn't remove light from your eyes, so holograms can't be rendered with the color black. Instead, black content appears as transparent.
Holograms can have many different appearances and behaviors. Some are realistic and solid, and others are cartoonish and ethereal. Holograms can highlight features in your surroundings, and they can be elements in your app's user interface.
Holograms can also make sounds, which will appear to come from a specific place in your surroundings. On HoloLens, sound comes from two speakers that are located directly above your ears, without covering them. Similar to the displays, the speakers are additive, introducing new sounds without blocking the sounds from your environment.
When you have a particular location where you want a hologram, you can place it precisely there in the world. As you walk around that hologram, it will appear stable relative to the world around you. If you use a spatial anchor to pin that object firmly to the world, the system can even remember where you left it when you come back later.
Some holograms follow the user instead. These tag-along holograms position themselves relative to the user, no matter where they walk. You may even choose to bring a hologram with you for a while and then place it on the wall once you get to another room.
Place holograms in the optimal zone - between 1.25m and 5m
Two meters is the most optimal, and the experience will degrade the closer you get from one meter. At distances nearer than one meter, holograms that regularly move in depth are more likely to be problematic than stationary holograms. Consider gracefully clipping or fading out your content when it gets too close so as not to jar the user into an unexpected experience.
Holograms aren't only about light and sound; they're also an active part of your world. Gaze at a hologram and gesture with your hand, and a hologram can start to follow you. Give a voice command to a hologram, and it can reply.
Holograms enable personal interactions that aren't possible elsewhere. Because the HoloLens knows where it is in the world, a holographic character can look you directly in the eyes as you walk around the room.
A hologram can also interact with your surroundings. For example, you can place a holographic bouncing ball above a table. Then, with an air-tap, watch the ball bounce and make sound when it hits the table.
Holograms can also be occluded by real-world objects. For example, a holographic character might walk through a door and behind a wall, out of your sight.
Tips for integrating holograms and the real world
As a holographic developer, you have the power to break your creativity out of 2D screens and into the world around you. What will you build?