Bridge

Bridge
Basic Info
VR/AR	Mixed Reality
Type	Head-mounted display
Subtype	Mobile VR
Platform	Bridge Engine
Developer	Occipital
Release Date	Explorer Edition: December 2016; wider release initially scheduled for March 2017
Price	Announced at US$399 with Structure Sensor and Bridge Controller; Explorer Edition US$499
Website	Historical: https://bridge.occipital.com/
Requires	Compatible iPhone and model-specific Bridge enclosure; original Structure Sensor
System
Operating System	iOS; iOS 9 or later reported at the 2016 announcement
Display
Display	iPhone display
Resolution	Depends on fitted iPhone; 640 x 480 per eye reported for the early headset
Refresh Rate	60 frames/s output reported in 2016
Optics
Optics	Interchangeable viewing lenses and lens spacers; separate 120-degree Wide Vision camera lens
Tracking
Tracking	6DoF headset; 3DoF controller
Positional Tracking	Inside-out tracking
Latency	10 ms camera-input-to-pose figure attributed to Occipital in 2016
Device
Sensors	Original Structure Sensor and iPhone camera
Input	Bridge Controller

Reviewed 15 October 2026. Original Bridge headset, historical phone enclosures, setup and software documentation, shipment reporting, retirement notice and one original point-cloud study. About review dates.

Bridge is an iPhone-powered mixed reality and virtual reality headset developed by Occipital. It combines the phone's camera and display with the original Structure Sensor to map a room and track the wearer's movement without external tracking cameras or a connected PC. Structure's support archive states that Bridge and Bridge Engine have been discontinued and are no longer actively supported. Its notice, updated on 24 October 2022, describes the remaining software as provided as-is without support.

Intro

Bridge uses video passthrough for mixed reality: the iPhone camera supplies the view of the surroundings, and the software combines that view with depth information and virtual objects. The wearer looks at the phone's display through the headset's lenses. In the 2016 demonstrations, this allowed a virtual robot to move around real furniture and portals to open into virtual environments.

The December 2016 announcement listed iPhone 6, 6s and 7 support, excluding Plus models. A later manufacturer compatibility FAQ lists separate headset models paired with iPhone 6s, iPhone 7 and 8, and iPhone X and XS. Those pairings describe particular enclosures, rather than universal compatibility with any iPhone; the FAQ was last updated in July 2022.

Features

The original Structure Sensor supplies depth data, while Bridge Engine uses that information with the iPhone camera to build a representation of the environment. The headset's inside-out positional tracking supports six degrees of freedom, allowing changes in position as well as head orientation. Its handheld controller supplies three degrees of freedom. This headset uses the original sensor: the manufacturer's assembly article specifically identifies it as the original Structure Sensor.

Bridge's room-mapping workflow begins with a scan of the floor, walls and furniture. In BRIDGET, the user selects Scan, moves the headset to cover the space and finishes the scan before starting the experience. The application can later load the saved map and relocalize in the same room. The archived guide warns that moving objects after a scan does not update the stored map.

The setup guide recommends furnished indoor spaces and identifies bright sunlight, reflective or transparent surfaces, and moving people as possible problems for operation. Chris Velazco's December 2016 demonstration report described the then-current software as tuned for an area of about 10 ft by 10 ft. That observation concerns the early demonstration's mapping scope, rather than a fixed physical range of the sensor or a guaranteed tracking area.

Hardware

Bridge holds the iPhone in a front enclosure with a magnetic clasp. The original quick-start guide identifies adjustable side and top straps, a rear pad and a ratchet adjustor. The Structure Sensor attaches with four screws to the mount above the phone, and a Lightning cable connects it to the iPhone. The sensor can also be removed and used separately, as Scott Stein noted in his contemporary demonstration report.

The sensor has its own rechargeable battery and barrel-jack charging connection. The manufacturer states up to four hours of continuous sensor use on one charge. Wired's December 2016 account described three to four hours per charge. This is a sensor battery claim, not a measured total runtime for the headset and iPhone together.

The 2017 guide documents removable viewing lenses and three lens spacers: 39 mm, 36 mm and 32 mm. Its reference ranges are respectively 0 to -1, -1 to -3 and -3 to -5 diopters. Occipital labels this as guidance for choosing a spacer and states that the inserts do not replace prescription glasses or contact lenses. The separate Wide Vision lens attaches in front of the iPhone camera; the manufacturer's 120-degree figure refers to that attachment, rather than a specified field of view through the eyepieces.

Controller

The Bridge Controller shown in the 2017 guide has a capacitive touchpad, two front buttons, a trigger and an indicator LED, and uses two AAA batteries. The guide describes connection through a Bridge-powered application and automatic shutdown after a minute without use. The archived setup article identifies the controller as a 3DoF device.

Technical Specifications

Component or figure	Documented scope
Phone support	Launch reporting: iPhone 6, 6s and 7, without Plus models. Later manufacturer pairings: 6s; 7 and 8; X and XS, with the appropriate headset model.
Operating system	iOS 9 or later in December 2016 reporting; this is a historical requirement, rather than a current software-support statement.
Display	Supplied by the fitted iPhone. The 2017 research apparatus used an iPhone 6S screen listed at 326 pixels per inch.
Early per-eye image	640 x 480 per eye reported in the December 2016 headset coverage.
Output and camera cadence	Sean O'Kane reported 60 frames/s output and a 30 frames/s camera feed in the December 2016 demonstration, with intermediate views predicted between camera frames.
Camera-input-to-pose time	10 ms attributed to Occipital by the December 2016 announcement report. This is not an independently measured motion-to-photon latency.
Tracking	6DoF headset tracking using the sensor/phone system; 3DoF controller.
Camera attachment	Manufacturer-described 120-degree Wide Vision lens, used during calibration.
Viewing-lens spacers	39 mm, 36 mm and 32 mm in the 2017 quick-start guide.
Connections and power	Structure Sensor-to-iPhone Lightning cable; separate sensor battery and AC charging adapter; two AAA batteries for the controller.

Software

Bridge Engine provides the software used to develop the headset's mixed reality applications. The archived developer tutorial describes a Unity plugin for creating a Bridge application or adapting an existing Google VR application to use its controller and positional tracking. It also identifies SceneKit as another way to write Bridge Engine applications.

Structure's retirement notice states that the original development kit remains accessible through its developer portal and GitHub, with no future Bridge development or support. This documents the vendor's stated distribution route; it does not establish that the old SDK builds or applications work with current phones, operating systems or development tools.

Apps

BRIDGET is the robot demonstration used to introduce Bridge's mixed reality features. In contemporary hands-on sessions, the robot retrieved virtual balls while navigating around real furniture; the demonstration also included virtual furniture placement and a portal into a space-station scene. The archived manufacturer instructions describe BRIDGET's scanning and loading workflow, including reuse of a previously captured room map.

Structure Sensor Calibrator prepares the sensor and camera combination before use. The manufacturer specifies one calibration per iOS device, with the Wide Vision lens installed. Its procedure uses a checkerboard target and finishes with a brightly lit, visually detailed scene. The App Store version history lists "Removed WVL Support" in version 4.6.0, dated 21 May 2025. The archived Bridge procedure describes the earlier application workflow; it does not establish current support for the camera-lens attachment.

Developer

The archived access instructions direct developers to request Bridge Engine through the developer portal and authenticate a GitHub account to access the Bridge Engine repository. The repository is described as requiring a GitHub login. The tutorials cover importing and building projects, using captured environments during development, and adding Bridge support to an existing Google VR project. The retired product's software remains subject to the as-is limitation stated by Structure.

Background

Occipital developed mobile computer vision software and was founded and backed by Techstars in 2008, according to its Techstars company profile. That profile dates the Structure Sensor launch to 2013. Before Bridge, the Structure Sensor was an iPad accessory for 3D scanning. Bridge adapted the sensor's depth-capture capabilities to a head-worn iPhone system, publicly demonstrated in December 2016.

History

Date	Documented event
9 December 2016	Bridge announced with an Explorer Edition priced at US$499 and a wider US$399 package planned for March 2017. The announcement report scheduled Explorer shipments for 16 December and described a single-button controller initially supplied with the 3DoF Bridge Controller to follow later.
December 2016	Explorer Edition shipments occurred in December, according to Chris Davies's later May 2017 hands-on report.
March 2017	Original target for the wider release. The December announcement establishes a forecast, not confirmation of shipment on that date.
23 May 2017	Davies reported that Occipital was preparing its second preorder batch with the new 3DoF controller, and described Bridge as already on the market. The report did not give an exact first-shipment date for the wider edition.
July 2022 compatibility documentation	Manufacturer FAQ lists model-specific iPhone 6s, 7/8 and X/XS pairings.
October 2022 retirement documentation	Support notice states Bridge and Bridge Engine are discontinued, without active support or future development. The page's update date does not establish the precise date sales or support originally stopped.

Contemporary demonstrations

Sean O'Kane found the positional tracking convincing in a short 2016 demonstration, but reported a visible delay and smudged imagery during motion. He also explained the difference between the camera's 30 frames/s input and the headset's 60 frames/s output. Velazco described the headset's balance favorably but found the eyepieces pressed against his glasses. Stein likewise reported tracking hiccups, fuzzy visuals and difficulty fitting the headset over his glasses. These accounts concern short demonstrations of early hardware and software.

Research use

Evangelos Alexiou, Evgeniy Upenik and Touradj Ebrahimi used Bridge with an iPhone 6S in a 2017 study of point-cloud image quality. Their custom application used Bridge SDK libraries and SceneKit to display original and degraded point-cloud objects side by side over a real tabletop. The experiment compared Gaussian positional noise and octree-pruning distortions in five objects using a five-level impairment scale. Twenty-four people participated, with 18 taking both sessions and six taking one, producing 21 ratings per stimulus before outlier rejection.

Participants could move around the objects, although the authors observed that many stayed in place. After rejecting outlying ratings, the analyses used 18 scores per Gaussian-noise stimulus and 20 per octree-pruning stimulus. The study demonstrates a particular laboratory use of Bridge for visual-quality assessment; its results concern point-cloud distortions and prediction metrics, rather than the headset's tracking accuracy or general comfort.