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John Carmack’s Keynote at Oculus Connect 2014 (Transcript)

Full Transcript of Oculus CTO John Carmack’s keynote at Oculus Connect 2014 where he discusses the Gear VR and shares development stories…

Operator: Ladies and gentlemen, please welcome CTO Oculus John Carmack.


John Carmack – Oculus CTO

All right. So I don’t actually have a presentation but I can stand up here and talk about interesting things till they run me off the stage.

So mostly that’s going to be about Gear VR because that’s what I’ve spent most of my effort this last year on. So for the too-long into listening crowd, we will start with where we are today and then we will go into the history and the path it took us there which offers some insight for the current state of things.

So I believe pretty strongly in being very frank and open about flaws and the limitations. So this is kind of where I go off message a little bit from the standard PR plan and talk very frankly about things.

So the current killer limitations on Gear VR are the fact that it’s a 60 Hz low persistence display which has flicker problems for a lot of people and it has no positional tracking, which is one of the critical aspects for DK2 in future products.

So there are plans and mitigation strategies for what we can do around that now and how we want to improve that in the future. The 60 Hz low persistence turns out to be — it’s not as tragic as a lot of people were expecting it. There were a lot of people just like that’s completely unusable and certainly Oculus has been talking about minimum frequencies for low persistence displays. And a lot of people were surprised that it wasn’t as bad as they thought it was going to be. But there are still broad ranges of sensitivities among people where for some people it really is bad and some people can’t even notice it, and problems with flicker sensitivity, because all the corners of the display screens both on DK2, basically all of our screens that are OLED based.

They have a cork in them where they don’t blur so much but there is a two frame rise problem. And many of you have probably seen this where it’s a type of ghosting but it’s not smearing like a full persistence display. But if you see especially like a dark tree limb in tuscani and you move your head very rapidly you will see one ghost of it, offset by certain amount proportional of your head movement speed. And that’s a problem that gets worse as the color palette gets dimmer. The very dark colors have more of a problem with smear.

This is something that we dearly want Samsung to fix in future displays but it hasn’t been their top priority to address but it matters in VR. We have made mitigation strategies for that where you can de-ghost where it’s kind of a software overdrive. If you know what color you put in there, you know what color you’re going to, if it’s higher you can actually drive it higher than what you want it to be to compensate for that problem.

And we’ve done that on both PC and mobile but it’s really another extra expense that’s hard to justify on mobile relative to all of our other problems and things that we want to spend our resources on. But still in general, darker games are an improvement. But unlike the problem with PCs and console games in the classic Doom 3 problem where if you make a really dark game, at least in VR when you can block out almost all the outside light that can be a much much more pragmatic workable solution than it is for a typical AAA game, where you have to worry about ambient lighting in the living room and so on.

So that’s one of the takeaways for Gear VR is the super bright pastel colored worlds. While they play well in VR from at a higher refresh rate, they have a drawback that you have to deal with and work around a little bit at the 60 Hz side of things.

The big one that is harder to mitigate though is the lack of position tracking. I mean we do all know, we’ve been talking about presence and how important it is to get that sub-millimeter tracking accuracy and we just — we don’t have it or any analog on mobile right now. And there are things that we’ve taken early steps on this – well, can’t you use like the AR applications to use the outward facing camera? And I have done integrations with QUALCOMM’s Vuforia and tried different things with that.

But some of the things that people miss when — if you pay attention carefully to these slides, one of the things on there is submillimeter no jitter — submillimeter accuracy with no jitter. And the current things that people can do with outward facing cameras for absolute positioning are really not close to that.

So we have — there’s not a great mitigation strategy for this other than all the things that people would do on DK1 to just try to not have the problem by not having things in the real near field where your body is not interacting with them the way you want them to. But there’s no really killer strategy to avoid that unless you’ve just got everything in the distance field, no stereoscopy and no near field effects. So that’s something that we just kind of have to grit our teeth and live with for now.

Now I have a scheme for both of these. I have things that I think are workable solutions that involve changes of the architecture that we may address these in the future. Because one of the things about kind of hitching our train with Samsung here is that they – Samsung’s technology ticks twice a year. They have big product rollouts two times a year and we expect Gear VR to be kind of following this path. So it’s not like it’s going to be years between updates here. There’s going to be hardware changes and updates and we can look at rolling out major new features as it goes on.

So the paths that I think can address these problems are: for the low persistence display, right now we achieved 75 Hz on DK2. Now DK2, if you’ve ever taken one of them apart, it’s basically a Note 3 screen. You know, this is a Note 4 screen with Gear VR. So they are very similar.

And the question might be asked: Well, why can’t we just run the Note 4 screen at 75 Hz like DK2?

So there’s couple aspects to that. There’s two things that we do to get the refresh rate on DK2. One of them is pulling out all of the blanking lines at the end of the blank. It’s a weird archaeology of technology thing that even LCD and OLED panels they still have vertical blanking lines as if they are CRT waiting for the raster to go back up to the top. And this is just, as display technologies have evolved, they have kept these historical artifacts. So there’s a little bit of margin where you can take all of those out and we would’ve been able to – and we did have one of the Galaxy — one of our earlier prototypes we could run it at 70Hz.

So the question was: Well, is it okay to run at 70Hz? Is that worth the improvement there? And the problem is a lot of things that we were looking at are going to be media related where you have – you want to be able to playback something that was captured with cameras, which is going to be usually a 60 Hz input.

In fact, one of the big achievements I think over the last year was getting a lot of the work in panoramic photography focused on 60 Hz instead of just 30 Hz capture. But that would’ve been probably a net negative for a lot of these things if we made a 70 Hz display that would make — it would add beat frequencies to anything playback at 60 Hz and it would make all the normal games about 15% harder to hit that target frame rate and that was a significant concern for us.

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