This is a detailed blog entry that explains the technological and manufacturing advancements that went into the North Star Project. Key questions inlcude:
What does hand tracking need to be like for an augmented reality headset? How fast does it need to be; do we need a hundred frames per second tracking or a thousand frames per second? How does the field of view impact the interaction paradigm? How do we interact with things when we only have the central field, or a wider field? At what point does physical interaction become commonplace? How does the comfort of the interactions themselves relate to the headset’s field of view?
Some techical decisions were:
- Inward-facing embedded cameras for automatic and precise alignment of the augmented image with the user’s eyes as well as eye and face tracking.
- Head mounted ambient light sensors for 360 degree lighting estimation.
- Directional speakers near the ears for discrete, localized audio feedback
- Electrochromatic coatings on the reflectors for electrically controllable variable transparency
- Micro-actuators that move the displays by fractions of a millimeter to allow for variable and dynamic depth of field based on eye convergence