Comment by hnlmorg
9 days ago
> 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.
> I also happen to know a thing or two about mobile computing hardware
You don't. You just don't. You haven't seriously thought about making an HMD. You haven't heard of those microdisplay vendors or had frantically searched how to cheat those electrical requirements. You haven't gutted a mobile device and held the shells and non-compute parts in hand. You haven't even torn apart a phone. You don't know how injection molded Mg chassis feel which don't sit right with your brain.
Your views and opinions and distributions of are based on user side stories and dopamine releasing qualities the elements offer, which is great for marketing existing or virtual products, but isn't well connected to underlying hardware. It's like human figures reconstituted from Penfield's Homunculus, made completely out of proportion.
I already brought up the shell. From the way you fixated on the battery after going through that part, it clearly didn't even come to your mind that the shells can be heavier than it, which I'm sure would be the case for a lot of battery powered HMDs.
You called DP Alt an underlying "protocol". It's DisplayPort. They're like one-way PCIe x1. Back of magazine Agilent vs Teledyne LeCroy stuffs. Besides you called XREAL displays "entirely dumb" when they have more than a 2D sprite engine on board. I know it does 3DoF warping when the host is not whispering the right command. It's a stupid feature but I'm doubtful PS2 can handle that.
And you keep insisting, what appear to boil down to, "use USB dumbass". Nothing about that make any sense.
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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.