CastAR

CastAR
Basic Info
VR/AR	Augmented Reality
Type	Optical head-mounted display
Subtype	PC-Powered AR
Creator	Jeri Ellsworth, Rick Johnson
Developer	Technical Illusions (later named castAR)
Release Date	November 2014 (early developer prototypes)
Price	US$189 Kickstarter starter tier (2013); US$400 development-kit preorder (August 2015)
Website	Original Kickstarter campaign
Requires	PC for the original projected-AR system
Display
Display	Two head-mounted micro-projectors
Resolution	1280 x 720 per eye in the January 2014 HD prototype
Refresh Rate	120 Hz per eye (campaign specification)
Image
Field of View	65° horizontal in projected mode (campaign specification)
Tracking
Tracking	Six degrees of freedom; camera tracking infrared markers
Connectivity
Connectivity	HDMI video and USB tracking in the original PC design
Device
Weight	Under 100 g target for the planned final glasses
Input	Game controller; proposed Magic Wand and RFID accessories

castAR was a projected augmented reality system developed by Technical Illusions, the company founded by Jeri Ellsworth and Rick Johnson after they left Valve. Its glasses carried two micro-projectors that sent stereoscopic images onto a retroreflective surface. Light returned toward the glasses, while head tracking changed the rendered perspective as the wearer moved.

The project included demonstrated prototypes, early developer hardware and plans for a later consumer system. These were different stages of development: early developer glasses shipped, but the company was still preparing a consumer launch when it shut down in June 2017.

Hardware

Glasses

The glasses had two projectors above their lenses and a camera that observed infrared markers near the projection area. In January 2014, Road to VR tried an HD prototype with 1280 x 720 projectors, replacing the lower-resolution projectors used in earlier demonstrations. Moving around the demonstration table changed the view of the virtual scene. The developers told the publication that this prototype had not yet been optimized for latency.

Technical Illusions specified 120 Hz refresh per eye for its planned glasses. Active shutters supplemented the separation provided by retroreflection. The developers designed the frame to fit over prescription glasses, and described a final weight below 100 g as a target. The campaign's high-fill-factor claim was intended to reduce the screen door effect; it was a design claim rather than a guarantee that every user would perceive no pixel structure.

In the original PC design, HDMI carried the video signal and USB connected the tracking camera. The campaign described local processing of camera images on the glasses, with tracking results sent to the computer. A contemporary hands-on account described an unobstructed infrared marker plate as necessary for tracking.

AR and VR Clip-on

The proposed AR/VR Clip-On redirected projector light toward the eyes through a near-eye optical path, allowing operation without the external retroreflective sheet. Its intended modes included see-through AR and an opaque virtual reality view. Precise camera tracking would still require infrared markers within view.

The accessory's announced functions should be distinguished from the demonstrated hardware. At CES 2014, Ellsworth told Road to VR that the clip-on prototype worked for only one eye and was not ready to demonstrate. Tom's Hardware also could not test the attachment in its early hands-on coverage.

Retro-Reflective Surface

The retroreflective material formed the projection area, for example on a tabletop. It returned most of the incident projector light toward its source, letting several wearers view the same surface with their own perspectives. The system could therefore show different views of one scene, or separate content, to people sharing a table. This arrangement required the special surface wherever projected images were to appear; the glasses did not project visible AR content onto arbitrary untreated objects.

Wand Controller

The Magic Wand was proposed as a handheld joystick and tracked 3D input device, with buttons, a trigger and an analog thumb stick. Reviewed reported that the wand was unavailable for its January 2014 demonstration. In August 2015, chief executive David Henkel-Wallace told Road to VR that the wand had been reworked to use the same tracking technology as the glasses.

RFID Tracking Grid

The proposed RFID Tracking Grid sat beneath the projection surface. It was intended to identify tagged cards, figurines and other physical game pieces and pass their identities and positions to software. A game could then associate a miniature with a virtual character or display information beside it.

Bases

The campaign offered bases designed to attach beneath existing miniatures. Ordinary RFID bases would identify pieces and provide coarse tracking. RFID Precision bases added a circuit board for two-way communication and more precise tracking; the advertised examples included controlling small motors or lights in a miniature. These descriptions belong to the accessory system proposed during development.

Specifications

The following figures describe the original campaign or identified early prototypes. They do not constitute a final consumer specification.

Part	Documented specification and scope
Display	Two micro-projectors, one for each eye.
Resolution	1280 x 720 per eye in the HD prototype demonstrated in January 2014; a combined 2560 x 720 across the two views.
Refresh rate	120 Hz per eye, specified in the campaign.
Field of view	65° horizontal for projected mode; 90° horizontal was specified for the proposed clip-on.
Tracking	Six degrees of freedom using a camera and infrared markers.
Rotational tracking	A gyroscope was planned as a Kickstarter stretch-goal addition, including operation without the infrared marker.
Positional tracking	Head-mounted camera observing infrared markers in the environment.
Update rate	120 Hz camera tracking, advertised in the campaign.
Latency	8.3 ms was the advertised tracking response time, rather than a measured end-to-end display-latency result.
Connectivity	HDMI for video and USB for the camera in the original PC design.
Input	A conventional game controller was demonstrated; the Magic Wand and RFID grid were additional proposed interfaces.
Weight	Under 100 g target for the planned final glasses.
Retro-Reflective Surface	The Kickstarter starter package included a planned 1 m x 1 m sheet; larger packages specified 1 m x 2 m.

Setup Tutorial

The original projected-AR arrangement combined a PC, the glasses, a retroreflective projection surface and an infrared marker visible to the tracking camera. The glasses received video over HDMI, while tracking used USB. The marker needed to remain visible as the wearer moved. This describes the historical PC setup; later announcements sought a self-contained consumer system.

Apps

Demonstrations focused on games played around a shared surface. In its December 2015 interview with Henkel-Wallace, GamesBeat described virtual marbles, battle chess and a wand-controlled block-stacking demonstration. The company was concentrating on tabletop experiences for the planned consumer product.

Research demonstrations and evaluations

A 2014 report by naval aerospace experimental psychologist Lt. Lee Sciarini described a CastAR prototype evaluation at Naval Air Station Whidbey Island. Naval aviation specialists tried projector glasses and retroreflective material with E/A-18G, E/A-6B and MH-60S aircraft as part of work originating in a Naval Postgraduate School class project. The report compared participants' opinions before and after the experience: ratings of potential training usefulness increased in 12 of 18 task areas. This was a subjective evaluation of a prototype, rather than a demonstration of improved flying skill; the short account did not report participant count or a controlled learning comparison.

Robert A. Sottilare and Joseph J. LaViola's 2015 I/ITSEC paper included CastAR in a feature and usability-heuristic evaluation of ten smart-glasses systems for adaptive land-navigation instruction. The authors considered its resolution useful for map detail, but judged its dependence on retroreflective material impractical for locations without training infrastructure. Their analysis used task requirements and usability criteria, not a reported controlled trial measuring learning with CastAR.

Developer

SDK and Unity integration

The campaign described a free software development kit exposing tracking data, rendering matrices and RFID data. It also proposed Unity integration scripts for the glasses, wand and tagged objects, plus example projects. Other engine integrations and support for existing VR applications were exploratory plans.

History

Valve research and crowdfunding

castAR began in Valve's hardware lab. Ellsworth's experiments in May 2012 led her to investigate projecting images onto retroreflective material. Her large early prototype was nicknamed the "head crab". The campaign's account said that this first apparatus used two cellphone-sized projectors and displayed a static image without tracking. Johnson began helping with software after discussing the project with Ellsworth in August 2012.

After leaving Valve in February 2013, Ellsworth and Johnson obtained permission to take the technology with them and continued through Technical Illusions. They demonstrated castAR at the Bay Area Maker Faire in May 2013.

The Kickstarter campaign ran from October 14 to November 15, 2013. Its 3,863 backers pledged US$1,052,110 against a US$400,000 goal. The US$189 starter tier offered glasses, built-in tracking and a 1 m x 1 m surface, with September 2014 listed as an estimated delivery date.

Early hardware and consumer plans

Early developer prototypes began shipping to Kickstarter backers in November 2014. In August 2015, Henkel-Wallace said about two-thirds of the hand-assembled prototype kits had shipped. At that point he forecast final developer kits for early 2016 and consumer hardware for late 2016 or early 2017. Development-kit preorders started at US$400, with the wand and clip-on priced separately.

On August 19, 2015, the company, now using the name castAR, announced more than US$15 million in Series A funding from Android co-founder Andy Rubin's Playground Global and its seed investors. Its announcement said working prototypes were already going to backers and described commercial availability in 2016 as an anticipated launch.

In December 2015, the company offered reimbursement to backers expecting hardware and a free consumer system when it launched. Henkel-Wallace told GamesBeat that the consumer release was then planned for 2017. The proposal addressed the difference between the developer hardware originally crowdfunded and the software and content expected by consumer backers.

On June 26, 2017, Polygon reported, citing former employees, that castAR had closed its doors and laid off fewer than 70 staff across Palo Alto and Salt Lake City. The report said further funding had not materialized and a small group was trying to sell the technology. The planned self-contained consumer glasses had still been due later that year.

Ellsworth later co-founded Tilt Five, which showed a separate tabletop AR system using retroreflection in 2019.

References

Reviewed 15 October 2026. Original castAR prototypes and campaign specifications, accessory plans, developer hardware, company history, and the stated limits of the 2014 Navy and 2015 I/ITSEC evaluations. About review dates.