A HoloArticle

Here is an update on my quest to stay on top of all things “holo:” HoloLamp and RealView “Live Holography.” While the two have really nothing to do with each other, both claim the “holo” label with varying degrees of legitimacy, and happened to pop up recently.


At its core, HoloLamp is a projection mapping system somewhat similar to the AR Sandbox, i.e., a combination of a set of cameras scanning a projection surface and a viewer’s face, and a projector drawing a perspective-correct image, from the viewer’s point of view, onto said projection surface. The point of HoloLamp is to project images of virtual 3D objects onto arbitrary surfaces, to achieve effects like the Millenium Falcon’s holographic chess board in Star Wars: A New Hope. Let’s see how it works, and how it falls short of this goal.

Creating convincing virtual three-dimensional objects via projection is a core technology of virtual reality, specifically the technology that is driving CAVEs and other screen-based VR displays. To create this illusion, a display system needs to know two things: the exact position of the projection surface in 3D space, and the position of the viewer’s eyes in the same 3D space. Together, these two provide just the information needed to set up the correct perspective projection. In CAVEs et al., the position of the screen(s) is fixed and precisely measured during installation, and the viewer’s eye positions are provided via real-time head tracking.

As one goal of HoloLamp is portability, it cannot rely on pre-installation and manual calibration. Instead, HoloLamp scans and creates a 3D model of the projection surface when turned on (or asked to do so, I guess). It does this by projecting a sequence of patterns, and observing the perspective distortion of those patterns with a camera looking in the projection direction. This is a solid and well-known technology called structured-light 3D scanning, and can be seen in action at the beginning of this HoloLamp video clip. To extract eye positions, HoloLamp uses an additional set of cameras looking upwards to identify and track the viewer’s face, probably using off-the-shelf face tracking algorithms such as the Viola-Jones filter. Based on that, the software can project 3D objects using one or more projection matrices, depending on whether the projection surface is planar or not. The result looks very convincing when shot through a regular video camera:

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On the road for VR: Microsoft HoloLens at Build 2015, San Francisco

I have briefly mentioned HoloLens, Microsoft’s upcoming see-through Augmented Reality headset, in a previous post, but today I got the chance to try it for myself at Microsoft’s “Build 2015” developers’ conference. Before we get into the nitty-gritty, a disclosure: Microsoft invited me to attend Build 2015, meaning they waived my registration fee, and they gave me, like all other attendees, a free HP Spectre x360 notebook (from which I’m typing right now because my vintage 2008 MacBook Pro finally kicked the bucket). On the downside, I had to take Amtrak and Bart to downtown San Francisco twice, because I wasn’t able to get a one-on-one demo slot on the first day, and got today’s 10am slot after some finagling and calling in of favors. I guess that makes us even. 😛

So, on to the big question: is HoloLens real? Given Microsoft’s track record with product announcements (see 2009’s Project Natal trailer and especially the infamous Milo “demo”), there was some well-deserved skepticism regarding the HoloLens teaser released in January, and even the on-stage demo that was part of the Build 2015 keynote:

The short answer is: yes, it’s real, but… Continue reading

Elon Musk discovers AR/VR

Serial entrepreneur Elon Musk posted this double whammy of cryptic messages to his Twitter account on August 23rd:

@elonmusk: We figured out how to design rocket parts just w hand movements through the air (seriously). Now need a high frame rate holograph generator.

@elonmusk: Will post video next week of designing a rocket part with hand gestures & then immediately printing it in titanium

As there are no further details, and the video is now slightly delayed (per Twitter as of September 2nd: @elonmusk: Video was done last week, but needs more work. Aiming to publish link in 3 to 4 days.), it’s time to speculate! I was hoping to have seen the video by now, but oh well. Deadline is deadline.

First of all: what’s he talking about? My best guess is a free-hand, direct-manipulation, 6-DOF user interface for a 3D computer-aided design (CAD) program. In other words, something roughly like this (just take away the hand-held devices and substitute NURBS surfaces and rocket parts for atoms and molecules, but leave the interaction method and everything else the same):

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On the road for VR: Augmented World Expo 2013

I’ve just returned from the 2013 Augmented World Expo, where we showcased our Augmented Reality Sandbox. This marked the first time we took the sandbox on the road; we had only shown it publicly twice before, during UC Davisannual open house in 2012 and 2013. The first obstacle popped up right from the get-go: the sandbox didn’t fit through the building doors! We had to remove the front door’s center column to get the sandbox out and into the van. And we needed a forklift to get it out of the van at the expo, but fortunately there were pros around.

Figure 1: Me, digging into the sandbox, with a few onlookers. Photo provided by Marshall Millett.

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AR Sandbox news

The first “professionally built” AR sandbox, whose physical setup was designed and built by the fine folks from the San Francisco Exploratorium, arrived at its new home at ECHO Lake Aquarium and Science Center.

Figure 1: Picture of ECHO Lake Aquarium and Science Center’s Augmented Reality Sandbox during installation on the exhibit floor. Note the portrait orientation of the sand table with respect to the back panel, the projector tilt to make up for it, and the high placement of the Kinect camera (visible at the very top of the picture). Photo provided by Travis Cook, ECHO.

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… and they did!

build their own augmented reality sandboxes, that is.

We still haven’t installed the three follow-up AR sandboxes at the participating institutions of our informal science education NSF projectTahoe Environmental Research Center, Lawrence Hall of Science, and ECHO Lake Aquarium and Science Center — but others have picked up the slack and gone ahead and built their own, based on our software and designs.

Figure 1: Augmented reality sandbox constructed by “Code Red,” Ithaca High School’s FIRST Robotics Team 639, and shown here at the school’s open house on 02/02/2013.

The newest addition to my External Installations page is “Code Red,” Ithaca High School’s FIRST Robotics Team 639, who just unveiled theirs at their school’s open house (see Figure 1), and were kind enough to send a note and some pictures, with many more “behind the scenes” pictures on their sandbox project page. There’s an article in the local newspaper with more information as well.

Together with Bold Park Community School’s, this is the second unveiled AR sandbox that I’m aware of. That doesn’t sound like much, but the software hasn’t been out for that long, and there are a few others that I know are currently in the works. And who knows how many are being built or are already completed that I’m totally unaware of; after all, this is free software. Team 639’s achievement, for one, came completely out of the blue.

Update: And I missed this Czech project (no, not that other Czech project that gave us the idea in the first place!). They built several versions of the sandbox and showed them off at hacker meets. And they say they’re currently trying to port the software to lower-power computers. Good on them!

Update 2: One more I missed, this time done by/for the Undergraduate Library at the University of Illinois, Urbana-Champaign. I don’t have any more information; but this is the YouTube video.

I should point out that these last two were news to me; I only found out about them after googling for “AR sandbox.”

So please, if you did build one and don’t mind, send me a note. 🙂 There’s a ready-made box awaiting your input right there ↓↓↓↓