Update: Please tear your eyes away from the blue lady and also read this follow-up post. It turns out things are worse than I thought. Now back to your regularly scheduled entertainment.
I somehow missed this when it was hot a few weeks or so ago, but I just found out about an interesting Kickstarter project: HOLOVISION — A Life Size Hologram. Don’t bother clicking the link, the project page has been taken down following a DMCA complaint and might not ever be up again.
Why do I think it’s worth talking about? Because, while there is an actual design for something called Holovision, and that design is theoretically feasible, and possibly even practical, the public’s impression of the product advertised on Kickstarter is decidedly not. The concept imagery associated with the Kickstarter project presents this feasible technology in a way that (intentionally?) taps into people’s misconceptions about holograms (and I’m talking about the “real” kind of holograms, those involving lasers and mirrors and beam splitters). In other words, it might not be a scam per se, and it might even be unintentional, but it is definitely creating a false impression that might lead to very disappointed backers.
In my detailed how-to guide on installing and configuring Vrui for Oculus Rift and Razer Hydra, I did not talk about installing any actual applications (because I hadn’t released Vrui-3.0-compatible packages yet). Those are out now, so here we go.
Kinect
If you happen to own a Kinect for Xbox (Kinect for Windows won’t work), you might want to install the Kinect 3D Video package early on. It can capture 3D (holographic, not stereoscopic) video from one or more Kinects, and either play it back as freely-manipulable virtual holograms, or it can, after calibration, produce in-system overlays of the real world (or both). If you already have Vrui up and running, installation is trivial.
If you are already running Linux, good for you. Skip the next paragraph.
If you don’t have Linux yet, go and grab it. I personally prefer Fedora, but it’s generally agreed[citation needed] that Ubuntu is the easiest to install for new Linux users, so let’s go with that. The Ubuntu installer makes it quite easy to install alongside an existing Windows OS on your system. Don’t bother installing Linux inside a virtual machine, though: that way Vrui won’t get access to your high-powered graphics cards, and performance will be abysmal. It won’t be able to talk to your Rift, either.
One of the first things to do after a fresh Linux install is to install the vendor-supplied drivers for your graphics card (if you don’t have a discrete Nvidia or ATI/AMD graphics card, go buy a GeForce!). Installing binary drivers is much easier these days. Here are instructions for Nvidia and ATI/AMD cards. If you happen to be on Fedora, enable the rpmfusion repositories and get the appropriate driver packages from there.
I just released version 3.0 of the Vrui VR toolkit. One of the major new features is native support for the Oculus Rift head-mounted display, including its low-latency inertial 3-DOF (orientation-only) tracker, and post-rendering lens distortion correction. So I thought it’s time for the first (really?) Vrui post in this venue.
What is Vrui, and why should I care?
Glad you’re asking. In a nutshell, Vrui (pronounced to start with vroom, and rhyme with gooey) is a high-level toolkit to develop highly interactive applications aimed at holographic (or fully-immersive, or VR, or whatever you want to call them) display environments. A large selection of videos showing many Vrui applications running in a wide variety of environments can be found on my YouTube channel. To you as a developer, this means you write your application once, and users can run it in any kind of environment without you having to worry about it. If new input or output hardware comes along, it’s Vrui’s responsibility to support it, not yours.
I wrote about my first impressions of the Oculus Rift developer kit back in April, and since then I’ve been working (on and off) on getting it fully and natively supported in Vrui (see Figure 1 for proof that it works). Given that Vrui’s somewhat insane flexibility is a major point of pride for me, what was it that I actually had to create to support the Rift? Turns out, not all that much: a driver for the Rift’s built-in inertial tracking unit and a post-processing filter to correct for the Rift’s lens distortion were all it took (more on that later). So why did it take me this long? For one, I was mostly working on other things and only spent a few hours here and there, but more importantly, the Rift is not just a new head-mounted display (HMD), but a major shift in how HMDs are (or will be) used.
Figure 1: The trademark “double-barrel” Oculus Rift screenshot, this time generated by a Vrui application.
My friend Serban got his Oculus Rift dev kit in the mail today, and he called me over to check it out. I will hold back a thorough evaluation until I get the Rift supported natively in my own VR software, so that I can run a direct head-to-head comparison with my other HMDs, and also my screen-based holographic display systems (the head-tracked 3D TVs, and of course the CAVE), using the same applications. Specifically, I will use the Quake ||| Arena viewer to test the level of “presence” provided by the Rift; as I mentioned in my previous post, there are some very specific physiological effects brought out by that old chestnut, and my other HMDs are severely lacking in that department, and I hope that the Rift will push it close to the level of the CAVE. But here are some early impressions.
Figure 1: What it would look like to unbox an Oculus VR dev kit, if one were to have such a thing.
So it appears the Oculus Rift is really happening. A buddy of mine went in early on the kickstarter, and his will supposedly be in the mail some time this week. In a way the Oculus Rift, or, more precisely, the most recent foray of VR into the mainstream that it embodies, was the reason why I started this blog in the first place. I’m very much looking forward to it (more on that below), but I’m also somewhat worried that the huge level of pre-release excitement in the gaming world might turn into a backlash against VR in general. So I made a video laying out my opinions (see Figure 1, or the embedded video below).
Figure 1: Still from a video describing how head-mounted displays should be used to create convincing virtual worlds.
This article is related to VR in two ways. First, the usual progression of overhyping the capabilities of some new technology and then falling flat on one’s face because not even one’s own developers know what the new technology’s capabilities actually are is something that should be very familiar to anyone working in the VR field.
But here’s the quote that really got my interest (emphasis is mine):
Others recall worrying about the presentation not being live, and thinking people might assume it was fake. Milo worked well, they say, but filming someone playing produced an optical illusion where it looked like Milo was staring at the audience rather than the player. So for the presentation, the team hired an actress to record a version of the sequence that would look normal on camera, then had her pretend to play along with the recording. … “We brought [Claire] in fairly late, probably in the last two or three weeks before E3, because we couldn’t get it to [look right]” says a Milo team member. “And we said, ‘We can’t do this. We’re gonna have to make a video.’ So she acted to a video. “Was that obvious to you?” Following Molyneux’s presentation, fans picked apart the video, noting that it looked fake in certain places.
Gee, sounds familiar? This is, of course, the exact problem posed by filming a holographic display, and a person inside interacting with it. In a holographic display, the images on the screens are generated for the precise point of view of the person using it, not the camera. This means it looks wrong when filmed straight up. If, on the other hand, it’s filmed so it looks right on camera, then the person inside will have a very hard time using it properly. Catch 22.
With the “Milo” demo, the problem was similar. Because the game was set up to interact with whoever was watching it, it ended up interacting with the camera, so to speak, instead of with the player. Now, if the Milo software had been set up with the level of flexibility of proper VR software, it would have been an easy fix to adapt the character’s gaze direction etc. to a filming setting, but since game software in the past never had to deal with this kind of non-rigid environment, it typically ends up fully vertically integrated, and making this tiny change would probably have taken months of work (that’s kind of what I meant when I said “not even one’s own developers know what the new technology’s capabilities actually are” above). Am I saying that Milo failed because of the demo video? No. But I don’t think it helped, either.
The take-home message here is that mainstream games are slowly converging towards approaches that have been embodied in proper VR software for a long time now, without really noticing it, and are repeating old mistakes. The Oculus Rift will really bring that out front and center. And I am really hoping it won’t fall flat on its face simply because software developers didn’t do their homework.
But let’s back up a bit. When it comes to VR, there are three prevalent opinions:
It’s a dead technology. It had its day in the early nineties, and there hasn’t been anything new since. After all, the CAVE was invented in ’91 and is basically still the same, and head-mounted displays have been around even longer.
It hasn’t been born yet. But maybe if we wait 10 more years, and there are some significant breakthroughs in display and computer technology, it might become interesting or feasible.
It’s fringe technology. Some weirdos keep picking at it, but it hasn’t ever led to anything interesting or useful, and never will.
One of the mysteries of the modern age is the existence of two distinct lines of graphics cards by the two big manufacturers, Nvidia and ATI/AMD. There are gamer-level cards, and professional-level cards. What are their differences? Obviously, gamer-level cards are cheap, because the companies face stiff competition from each other, and want to sell as many of them as possible to make a profit. So, why are professional-level cards so much more expensive? For comparison, an “entry-level” $700 Quadro 4000 is significantly slower than a $530 high-end GeForce GTX 680, at least according to my measurements using several Vrui applications, and the closest performance-equivalent to a GeForce GTX 680 I could find was a Quadro 6000 for a whopping $3660. Granted, the Quadro 6000 has 6GB of video RAM to the GeForce’s 2GB, but that doesn’t explain the difference.
