Virtual Reality Basics

[Guest]

Join us as we take a quick look at the most prominent players, technologies and terminology in the modern world of virtual reality.

Virtual Reality Basics : Read more

 

[hdmark]

Good read! Covered pretty much everything ive glanced through in the last few months. Looking forward to an update to this in a few years !!

 

[tylanner]

After the significant technological progress recently there has been a shift in focus towards improving ergonomics and wearer comfort.

Improving on the heavy and obtrusive 1.0's will go along way for overall immersion and natural mobility.

 

[utgardaloki]

What do you mean the resolution is 2160x1200 per eye on the Rift and HTC Vive? As far as I've heard both companies state it's supposed to be 2160x1200 combined for both screens so 1080x1200 per eye.

So 2160x1200 total. Not 4320x1200 total.

Can anyone confirm?

 

[FlukeRogi]

@utgardaloki - you're correct, the article is wrong.

Overall resolution is 2160x1200 as you said, giving 1080(horizontal) x 1200(vertical) per eye.

 

[Enterfrize]

Hi there!

I'm the actual author. The resolution as written for the Oculus CV1 is indeed incorrectly written in the article. It's 2160X1200 spread over two displays (not multiplied by two). The article was written months ago before the CV1 details were actually confirmed, which is why other details are a bit out of date as well (e.g. Project Morpheus instead of PSVR). We'll get this cleaned up - I just noticed that it was published today. I completely forgot this article was in the can for much later; I should have been more diligent and followed up on the finer details before this had the opportunity to see the light of day. Sorry for the inconvenience.

Regards,
Neil

 

[Enterfrize]

Hi there!

I'm the actual author. The resolution as written for the Oculus CV1 is indeed incorrectly written in the article. It's 2160X1200 spread over two displays (not multiplied by two). The article was written months ago before the CV1 details were actually confirmed, which is why other details are a bit out of date as well (e.g. Project Morpheus instead of PSVR). We'll get this cleaned up - I just noticed that it was published today. I completely forgot this article was in the can for much later; I should have been more diligent and followed up on the finer details before this had the opportunity to see the light of day. Sorry for the inconvenience.

Regards,
Neil

 

[Enterfrize]

Just got word that the fixes will be implemented shortly. Don't worry; even at 2160X1200 pixels, VR is loads of fun!

Regards,
Neil

 

[FritzEiv]

Sorry folks. I've updated the Oculus CV1 specs and am making a few other modifications, none of them of that level of significance, thankfully.

-- Fritz Nelson, Editor-in-chief

 

[beetlejuicegr]

Asynchronous Timewarp Don't you love it when new words are used for old stuff? This "tech" is used on online games to compensate for the high latency of some players.
Also awesome example was the "zero ping" mod in unreal tournament which was kinda doing something similar for your bullets and aiming

Seriously though, this article is super awesome and i will bookmark it for some time, because i intend to buy one VR in a year or so too.

 

[Schepkens Hendrik]

WE ARE VR!
http://ecx.images-amazon.com/images/I/91kfurYwTCL._SL1500_.jpg

 

[ilter]

So.. New technology is acceptable, but will be brings lot of medical problems with this type. Its not easy convenient tool for us.I wanna use VR on treadmill. Not like these.I m not astronout.

 

[Murissokah]

Can we take a minute to talk about how VGA frames per second and display frequency are not so closely related as the article seems to imply? It is an incorrect assumption that one needs XX FPS in order to display at XX hertz. While it is pretty obvious that a display that refreshes slower than your VGA buffer will not be able to display all of the information on the screen, it is possible that this information would not be perceived in the first place. On the other hand if a display refreshes faster than the buffer, this may or may not be perceived by the eye.

Cinema displays have managed to convey fluid motion from long ago by using 24fps imagery with some motion blur. On the other hand, games with very sharp and fast-moving graphics can become choppy at much higher refresh rates, because the changes in detail are much more abrupt.

The theory behind this comes from the Nyquist-Shannon sampling theorem, which in short states that the sampling frequency of a sampling device should be (at least) twice that of the highest frequency component sinusoidal contained in the sampled signal, otherwise aliasing will happen. This means that the occurrence of aliasing and consequent loss of information depends on both the characteristics of the original signal and the frequency of the sampling device. Thus, a digital imaging device may be able to display losslessly a given input signal but not another.

In the case of digital imagery, there are two sampling steps involved, the first occurs when the monitor samples the VGA buffer and the second one when our eyes sample the image on the screen, this last one being the one that matters most. I had some reservations treating the human eye as a digital sampling device, but these guys seem to know a lot about it and did apply this same theory:

http://xcorr.net/2011/11/20/whats-the-maximal-frame-rate-humans-can-perceive/
http://redwood.berkeley.edu/bruno/npb261/aliasing.pdf


So in short, if my limited knowledge is to any credit, a 75hz display doesn't really require 75 FPS to work properly, there are other things that come to play in this. The higher frequency is welcome in any scenario, though.

 

[picture_perfect]

It is an incorrect assumption that one needs XX FPS in order to display at XX hertz.

No, they should match and here is why:
fps > hz = tearing (everyone has seen these horizontal break lines)
fps < hz = judder (third pic from the bottom is a perfect example)
fps = hz = visual bliss

The Nyquist theorem applies to analog-to-digital-conversions but monitors sampling discreet "frame packets" from a video card are more analogous to digital-to-digital conversions. In that case, sampling frequencies (hz) higher than the frequency of samples (fps) may return null samples (forcing frame repeats, i.e. judder). Sampling frequencies (hz) lower than the frequency of samples (fps) may gather multiple incomplete samples (multiple frames per refresh, i.e. tearing). But if sampling frequency = frequency of samples (hz=fps) and both are in sync (v-sync) no information lost or incomplete! Visual bliss.

 

[gaaah]

Great article. Saved me a lot of time by distilling all the disparate info out there. What a mess the field is right now. I've always been a late adopter. I'll be perfectly content to wait out the ensuing standards survival-of-the-fittest contest. When will it settle out? DirectX 15? Probably several years.

On another track, I imagine this stuff is really addictive., I wonder if we will see the emergence of the "VR junkie" --and by that I mean more than just a few Asian kids that play themselves to death. I wonder if it will become a real problem, much like the drug problem is now. Time will tell.

 

[lorrraa3544]

►œ►œ►œ►WWW.netweb30.com

 

[TheChuckster]

"Valve's HTC Vice [sic]"

Really???

 

[Enterfrize]

"Valve's HTC Vice [sic]"

Really???

That's funny! Gotta fix that one. That darned "C" was next to the "V".