Pixel Persistence & Motion Blur as Fast As Possible
Techquickie
·Techquickie
·2015-05-07
·
1,215 words · ~6 min read
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So, you got your expensive graphics card, your overclocked octaore CPU, and
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more memory than a freaking elephant. But when you're playing the latest AAA
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games on your PC, or really anything else, for some reason, things don't seem
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quite right. Especially when you're looking at a scene where a lot of things
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are moving around at once or the camera's panning. Because even with all
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that horsepower under the hood, motion blur is a problem on even the most
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powerful rigs. And if you're gaming on a VR headset like the Oculus Rift, it can
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be even more distracting. Now, to be clear, we're not talking about the kind
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of motion blur that is intentionally added to a game in post-processing. What
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we're talking about is unintentional motion blur caused by excessive pixel
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persistence. You see, an electronic display, whether it's a computer monitor
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or a headset or a phone, is made up of millions of individual pixels that
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change their brightness and color to create an image that you see. So,
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whenever the image on the screen changes, which is nearly constantly if
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you're playing a game that isn't Pong, the pixels cannot respond
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instantaneously. With a typical LCD monitor, there's actually delay of a few
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milliseconds before the pixels can actually change. Now, while there are
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fast response monitors which have a delay or response time of just 1 or two
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milliseconds, which helps to cut down on motion blur significantly, even those
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don't completely solve the problem. In fact, even if a zero millisecond monitor
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existed, there's still an issue with how LCD displays actually show images to us.
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Like other pieces of digital hardware, an LCD display works by sampling image
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data it gets from the computer many times a second and displaying the
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samples as a series of still images.
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These still images are then displayed at a rate equal to your screen's refresh
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rate, usually 60 Hz, and your brain interprets this as movement. However,
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your eye is not a piece of computer hardware, unless of course your name is
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Adam Jensen. Human eyes are really good at perceiving differences in fluid
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motion. And while high refresh rate displays that operate at 144 hertz or
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even higher look great, they still can't
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completely fool our brains just by showing us a series of static images.
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And as if the problem of motion blur weren't bad enough on computer monitors,
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it's much worse if you're using an Oculus Rift or VR headset like I
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mentioned before. While motion blur might just be an annoyance if you're
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gaming in 2D on a desktop PC, it can actually make you sick on a 3D display
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like the Oculus Rift. Because these headsets work by surrounding your field
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of vision in immersive 3D environments, motion blur in these situations can make
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you feel physically out of balance with
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your surroundings and cause a very similar nausea to what you'd feel in a
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car or an airplane in the same situation. So, the solution itself is a
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pretty simple idea. Well, let's just cut down on how long individual pixels are
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displayed so that we don't we're not out of sync. But how are display
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manufacturers going to accomplish this? Well, one way is through a technique
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called backlight strobing. Typically, modern LCD monitors are illuminated by a
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backlight that's always on. However, in a display that uses backlight strobing,
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the backlight instead switches on and off rapidly, reducing the amount of time
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that you actually see each pixel. This is very similar to the way that CRT
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displays, which were, you know, for the kids that weren't alive in the time of
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the dinosaurs, which are those old tube things that existed before LCDs came
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onto the market, and is the reason that CRTs have historically been better at
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displaying scenes with fast motion, at least to our eyes. There are a number of
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monitors on the market that feature backlight strobing combined with high
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refresh rates to reduce motion blur as much as possible while still maintaining
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the picture quality and low energy consumption, not to mention the space
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savings of a flat panel LCD. Of course,
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it's also possible to ditch the backlight altogether and go a different
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route. So, the consumer version of the Oculus Rift features a display based on
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organic LEDs or OLEDs. OLEDs can
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generate their own light through the use of specialized organic compounds. But
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more importantly for gamers, OLEDs have a very quick response time, much faster
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than the pixels in a conventional LCD. And not only does this cut down on
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motion blur on its own, the low response times allow OLEDs to interpolate frames
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easily, meaning that your system can guess missing frames in a given second
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to match your display's frame rate. Or if you're just watching a movie recorded
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at the usual 24 FPS and you want your experience to be less cinematic, I guess
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it could do that, too. So whether you're gaming in 3D using a headset or just a
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monitor with 3D glasses, these technologies will help you do your thing
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without feeling like you're on some kind of vomit inducing carnival ride.
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already. I told you I have to host this because you just can't do a good enough
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This is ridiculous. I've I've been trying to build this company for like 2
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years. We don't have to roll the camera on this. Like, okay, look, if you need
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to talk about this, then you need to talk to yourself about how you run the
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company. No air conditioning. People are like overheating all the time. Um, I'm
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working while I'm sick. I have to get my doctor's appointment because I have to tape you up. Look, I think What even is
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that? Like I've been sick for like 2 months. I finally get a doctor's
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appointment with my family doctor and you don't you make me not go because of
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masking tape. Well, I think you're I think Look, okay, but we were supposed
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to have you do the spot and you were supposed to do Josh's thing. I get
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dragged into the office and I have to film this. It's not like I wanted to
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like Okay, you know what? Just I'm done.
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We'll talk later. No, I'm just done.
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You
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um so sorry. I hope that wasn't too awkward. Guys, like the video if you
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liked it. Dislike it if you disliked it. Leave a comment. Um, if you have
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suggestions for future fastest possibles that I guess won't be hosted by Luke.