Comment by numpad0
8 days ago
XREAL is DisplayPort Alt Mode + USB for gyros. It's also wired only. DP needs 10-40Gbps of bandwidth, doesn't work wireless.
USB cameras also aren't natively supported on iOS/Android. You need apps. With apps comes lock-in opportunities which are never not tapped.
So "just use USB" doesn't make technical sense at all.
> XREAL is DisplayPort Alt Mode + USB for gyros. It's also wired only.
I know what Xreal uses. As I said, I have a pair
> DP needs 10-40Gbps of bandwidth, doesn't work wireless.
And as I also said, having a cable is a feature, not a problem.
VR headsets are heavy and uncomfortable. USB powered XR glasses are not. And the reason for that is because you don’t need to make those XR glasses as literal portable computers with heavy batteries.
You might relish the idea of an ugly monstrosity that weighs as much as a laptop strapped to your head. Myself, I’d much rather have something that look and feel like sunglasses. If that means I need a discreet UsB cable behind my ear, then thats a small price to pay because they’d still look less stupid than wearing anything bulkier out in public.
> USB cameras also aren't natively supported on iOS/Android. You need apps. With apps comes lock-in opportunities which are never not tapped.
That’s not a limitation for all platforms though. And you’d have that problem on Android whatever solution you opted for. So it’s a moot point.
> So "just use USB" doesn't make technical sense at all.
It does and plenty of people, myself included, owning a pair of Xreal glasses are proof of that.
The problem here is not USB, it’s that you have very specific differing requirements and thus are dismissing the practical value myself and others have shared.
> VR headsets are heavy and uncomfortable. USB powered XR glasses are not. And the reason for that is because you don’t need to make those XR glasses as literal portable computers with heavy batteries.
no it's lenses and chassis. Lenses work precisely because of their density difference against air, so the better they are, the heavier they are. Chassis weigh a lot because they use impact resistant ABS and don't make them in forged Al-Li or Ti or molded Mg, which they should consider for hilarity, but then the product will cost like a bad joke. The mobile computer part weighs nothing, they're like somewhat soggy potato crisps. Those 0.8mm PCBs, boy they feel like cardstocks. Batteries weigh a bit, but they're also usually lipo pouches, like 0.5kg/L. You're not putting dozen 18650 into a VR headset.
Especially VR lenses are heavy and bulky because they need short focal lenses with massive pupils for max FOV and max transmittance. The panels tend to be way bigger than that for smart glasses thanks to Palmer Luckey which he deserves credit for. Smart glasses tend to use way smaller panels and prisms with fractions of FOVs relative to VR, like 1/6th? 1/12th? They carry some amount of weight but not nearly as much, especially if it's waveguide or holographic or working as pure fresnels.
I'm not going into the second half of this response. I am sorry but I don't think it's worth anyone's time if I explained why DP Alt don't count as USB and all that stuffs.
You’re arguing a lot but ignoring what other people are saying. It’s pretty clear from your other comments that you have distain for “software jockies”, but that doesn’t mean that we are idiots who don’t understand how hardware works.
Case in point: even if you took the lenses out, they’d still weigh more than a pare of sunglasses. You even admitted that yourself, but then you quickly brushed over that point.
So does it really matter that lenses are also heavy when we are talking specifically about the battery?
I also happen to know a thing or two about mobile computing hardware and there’s a bunch of stuff you’ve also neglected to mention that would add weight. But ultimately the battery alone is a compelling enough argument.
Let’s also remember that I wasn’t just talking about weight but bulk too. Even if you could get the weight down so it’s comparable to a pare of glasses (you couldn’t, but let’s assume for the moment that you do manage to break the laws of physics), it’s still going to be bulkier than a pair of glasses.
So even if you were right that the lenses were the only thing that matter about weight (which you’re not), it’s still just a moot point.
> I'm not going into the second half of this response. I am sorry but I don't think it's worth anyone's time if I explained why DP Alt don't count as USB and all that stuffs.
I’m not an idiot. I’m well aware that Xreal are using DP, and I’ve already pointed out before.
My point is all I need to do as an end user is plug in a USB-C cable and everything “just works”. The underlying protocol is largely irrelevant. It’s like saying “you’re not using wireless, you’re using 802.11ac…” literally zero consumers give a shit because it’s completely irrelevant to the UX of the device.
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> discreet UsB cable behind my ear
If someone could create a fashionable, transparent usbc cable, perhaps replacing copper with indium tin oxide, it might change people's minds about wired.
A real user-centric OS (like a full-fledged Linux distribution, not something intentionally crippled as badly as Android) would use something like PipeWire[1] for this. It's a project designed entirely around managing multiple multimedia devices so they can be accessed by multiple applications, even concurrently.
[1] https://pipewire.org/
PipeWire? I don't think you want that kind of thing for raw video output. You want display content to be on VRAM. The void between software jockeys and hardware world sometimes makes me feel numb.
> The void between software jockeys and hardware world sometimes makes me feel numb.
Comments like the above are completely unnecessary and against the rules on HN
"USB cameras also aren't natively supported on iOS/Android. You need apps."
The attachable endoscope for my Ulefone Armor would disagree. It works with the stock Android camera app.
Lo and behold, you just need DRIVERS.
Did they finally implement UVC in Camera2/CameraX? I thought that had been Soon(TM) for years.
No, you just implement the Camera2 API and camera HAL interface in your driver so your device can talk to all the applications that call that API.
Some people prefer wired because of external battery, bandwidth, signal stability and integration/interop (e.g. usbc hubs). There are always tradeoffs in designs.