The smallest VR headset I’ve ever tried: hands-on with GravityXR

I promised to keep you informed about the cool things I could have tried in China. And I’m keeping my promise with this article in which I tell you about my hands-on with the GravityXR reference design VR headsets. I’m pretty sure you will love it, because one of these headsets is incredibly small… probably the smallest VR headset I’ve ever tried until now!

[Notice: I tried these headsets only for a few minutes, so consider this a “first impressions” article and not a full-fledged review]

GravityXR

GravityXR is a Chinese company based in Shanghai that specializes in the design and production of chips for AR/VR headsets. I thought in the beginning that this company was a sort of headset manufacturer, but actually, they don’t do headsets; they create the chips and the reference designs for the OEMs to use to produce their own headsets.

Imagine it as a sort of “Chinese Qualcomm”. The two companies don’t exactly do the same things (for instance, I’ve been told that Qualcomm does System-on-Chip devices, which GravityXR usually doesn’t do), but I guess the comparison conveys the idea. The company can cooperate with vendors in various ways. For instance, they can just provide the chips, and the companies can build a whole headset around it. Or they can provide the chips and the reference designs, and the OEMs may start from this to create their own XR products more easily.

The company was established in 2021. Since then, it has received various funding rounds and now is able to offer a few chipsets and reference designs. Let me tell you more about them.

GravityXR chips

GravityXR currently offers three chips to its customers:

• GravityXR X100: the chips for mixed reality headsets. It is like the R1 chip on the Vision Pro, the one handling all the “mixed reality stuff”, so that the M5 can give its full power to the running application. This chip can basically handle the positional tracking, the mixed reality passthrough, the sensor cameras, and all the rest that is necessary for an MR headset to run

• GravityXR VX100: the chips for smartglasses. It is like the Qualcomm Snapdragon AR1 that is installed in the Ray-Ban Meta glasses. GravityXR claims that this has the advantage of being much smaller than its Qualcomm equivalent, so it allows for the creation of smaller AI glasses. This is the ideal ISP chip for AI glasses

• GravityXR EB100: the chips for robots and MR. This chip has been conceived as a dedicated unit to offer reverse passthrough on mixed reality headsets. Reverse Passthrough is what Apple calls “EyeSight”, that is, seeing the eyes of the VR user, thanks to a screen installed on the front of the headset. Given the relatively low interest in this feature, it has been mostly repurposed to support robotics applications.

During my time at GravityXR offices, I‘ve tried only reference designs based on the X100 chipset, which has intriguing features like:

• Support for sub-10 ms photon-to-photon (P2P) latency
• Full-pipeline support for gaze-dependent rendering, with binocular 8K/120 Hz output
• Power consumption as low as 3 W
• Cross-OS compatibility.

Hands-on with the G-X100-M0 Reference Design

The first headset I tried was a reference design for PCVR mixed reality headsets. This device was basically a PC-connected Apple Vision Pro.

The main specs were:

• 4K OLED displays per eye
• 90Hz refresh rate
• 105° FOV
• 6DOF
• Eye-tracking and hand tracking support.

After I did the calibration for eye tracking (with the usual dots to look at), I could see in front of me a clone of the Vision Pro menu, and I could interact with it using gaze and pinch. Eye tracking was performing rather well, and looking at a menu item caused it to react. Hand tracking was kinda working too, but it was very slow: there was a noticeable lag between my hand movements and what the device was tracking. Still, for the pinch interaction and also the other simple interactions needed by the UI, it was absolutely fine.

Using the menu, I could open the mixed reality applications and see them in front of me. I have tried things like:

• Seeing the 3D model of a motorcycle that I could rotate and zoom
• Watching a 3D movie on a big screen in front of me
• Opening a virtual reality portal in the room
• Entering into a virtual environment and changing the amount of real and virtual by using a hand UI

Interactions happened mostly via hands. I could activate a menu attached to my hand and press the buttons with the index finger of the other hand. With the left hand, I could pinch in the air, and by moving the hand, I could slide up and down and decide the amount of virtuality I wanted to have in my environment. I could also open the main menu with a special gesture.

This headset had for sure great visuals: the 4K OLED screens gave insane resolution and very crisp colors. The passthrough quality was also very good, probably in line with the best passthrough vision of today: it was not as good as real-life vision, but I could clearly read all the text in front of me. What disturbed me a bit was that I could perceive a sort of lag in the headset… I can’t explain if it was like tracking lag, performance-driven lag (the PC couldn’t render fast enough), or whatever… I can just say that I had the slight impression that something was not perfect in how the images were shown to me. Also, the border of the lenses showed some spherical aberration (which happens on all headsets) and a little warping. I also had a couple of snaps of the positional tracking. There was also a little persistence blur if I rotated my head fast. All in all, the result was good, and the great resolution made me forget most of the little problems.

There are also magnetic prescription lenses that can be used with this reference design.

Hands-on with the G-X100-M1 Reference Design

So now let’s get back to the most interesting part of my visit: the very small headset! The G-X100-M1 is another reference design, always of a tethered headset. But this time it is focused on offering a very compact size. Here are some photos I took of it:

And here are some specs:

• 2.5K OLED display per eye
• 90Hz refresh rate
• 75° FOV
• 3DOF/6DOF depending on the platform
• Hand tracking support
• 93.6g of weight

As you can see, some sacrifices have been made compared to the previous version to accommodate the small form factor:

• The FOV is dramatically smaller
• Eye tracking disappeared
• The resolution of the displays is smaller

The interface of this device was again copied from the Vision Pro, but in this case, since eye tracking was not supported, instead of having the gaze on menu items, I had to look with my whole head and pinch. Honestly, it is not a great UX (eye tracking is infinitely better), but for a demo, it can work.

What I saw here depended on the platform. These glasses could be connected either to a Windows PC or to an Android Phone. In the case of the Windows PC, which could also be a Windows console, I had a similar experience to the previous PCMR headset, but without eye tracking. I had a Vision Pro menu from which to launch MR applications, and I could see them using 6DOF tracking.

It was intriguing that the glasses could also be connected to an Android Phone. Currently, the phone has to run a custom build of the operating system, but GravityXR is working so that in the future, people can just install an app on their personal phone, and then the glasses can work. In Android, the system is currently only 3DOF, but the company is working to reduce this limitation. Interaction is always with a Vision Pro-like menu, but, interestingly, you can also launch the standard 2D apps installed on your phone, and see them in a floating screen in front of you that you can move around using your hands. With this configuration, I also tried some demos I didn’t try with the other units:

• A few 360 videos
• A few 2D apps like TikTok and WPS Office that I put in the space around me.

The glasses, in general, were good. Thanks to OLED, colors were bright, and because of the low FOV, the pixel density was definitely good, and images appeared very well defined.

But I still had the same “lag” thing I noticed in the other unit, and I still saw some aberrations on the border of the lens. But these were not big issues. The big issues were mostly two:

• The FOV of 75 was very limiting. If you’re using the headset for AR/MR, it’s still kinda ok, because the glasses have an open periphery, so you have the full vision of the real world besides the small region with the passthrough. This gives the illusion of a full 200° vision. But if you want to enjoy some virtual content, it is barely acceptable: it is enough that you can actually enjoy the experience, but not enough to immerse you in it. So I think these glasses are more suited for MR than pure VR

• The chip overheated quite a lot. The chip is installed exactly at the center of the glasses, and so it was exactly in the region at the center of my eyes. And I could feel this area becoming very warm. I reported this problem to the company, and they told me that they are working on improving this, but that it’s also more of a problem of the company implementing the reference design instead of their own. The OEM using GravityXR chips can, for instance, use a better fan or better materials to offer better heat dissipation.

On the good side, the passthrough quality was definitely good: again, not like the real vision, but with a quality good enough to read texts. Speaking with the company, I learned that they spent a lot of time optimizing two things:

1. The passthrough latency, which is now 9ms, the lowest I’ve ever heard on a mixed reality headset
2. Reduce the seam in the transition from the passthrough part of your vision to the see-through one. Basically, the idea is that if you move your left eye from the full left to the front, you should theoretically see just one reality, without seams, notwithstanding the fact that your vision is comprised of a see-through periphery and a pass-through vision mediated by screens in front of you. Actually, GalaxyXR did a good job on this, even if, to say the truth, I could still see the black seam of the frame between the two areas, and I could also see a slight misalignment between the real world and the virtual one. But it was visible that they worked hard on this, because the seam was much better than I thought.

Talking about the comfort, the 93.6g weight was ridiculously low. I’ve been told my unit was not optimized for Western faces, but it was so light that my nose was not perceiving any discomfort. You almost don’t feel the weight of this VR headset; it’s insane. I’m pretty sure that you could feel discomfort after a few hours wearing it (the all-day comfort is below 50g), but for a short demo, it was amazing. This is for sure one of the biggest strengths of this headset.

These glasses also support magnetic prescription lenses.

Price and release date

GravityXR doesn’t want to reveal the prices of its prototypes. But it is already collaborating with some OEMs that should announce VR glasses based on the GravityXR X100-M1 reference design, probably already this year.

The company is also looking for OEMs that want to collaborate with it, so feel free to get in touch (or ask me for an introduction) if you are considering integrating its chips. They also told me that occasionally, they could even sell a few prototype headset units to companies and institutions that may be interested in using them.

General impressions on GravityXR

I’ve come out pretty impressed by my hands-on with GravityXR reference designs. For sure, the size of the M1 prototype was impressive: I’ve never worn a headset that looks like glasses. Of course, it is not as small as real glasses… internally it is much thicker, but it is still incredibly small if compared to other headsets. And it’s infinitely lighter than other headsets: it’s almost like not wearing it. The quality of the visuals of both prototypes was also crazy good: good colors and high definition, thanks to high-density micro OLED displays.

At the same time, there are still some small issues here and there that the company should iron out in subsequent iterations of its reference designs. The thermal one was the biggest one in my opinion, because I can not think of wearing for a long time a device that overheats close to my brain. As for the small FOV of the M1 unit, I don’t consider it a bug, but a design choice, which sacrifices FOV for size and comfort. It is anyway, a huge compromise that may hurt some experiences.

As for the comparison with Qualcomm, I think that it’s good that GravityXR is offering an alternative. Competition is always good for the ecosystem. Now, thanks to it, we can have headsets that are very lightweight and that can work both with the phone and the PC. At the same time, Qualcomm has been doing XR reference designs for years and has collaborated with many big brands on releasing various devices on the market. GravityXR is rather new to this game, so it still has to iterate on its designs and also to offer a better and easier integration to its partners.

But I think it is on a good path to deliver its vision. The headsets I tried today are definitely interesting, and I really hope that this company can keep up its great job.

(PS Thanks to Joel for helping me go through the demos!)