Anti-Aliasing and Monitor DPI

[Geo]

http://www.theinquirer.net/?article=29655 Some discussion/prediction there of a move to 150dpi from 96dpi.

Would higher pixel density on monitors make FSAA less necessary?

 

[Diplo]

Higher pixel density would probably make it unfeasible (for many current cards!)

 

[Albuquerque]

Higher pixel density would probably make it unfeasible (for many current cards!)

Well, technically density alone wouldn't do it, but since people probably aren't going to enjoy playing games at a physical display size of a post card, you're generally right

"Smaller" pixels really still doesn't solve aliasting in entirety. There will still be cases with 1pt high-contrast edges where AA will still be needed. Same goes for alpha textures and aliasing within textures.

 

[Blazkowicz]

there's some Inqu bullshit, such as about the 30" screens

There are a few problems here. Firstly, they can't display full-screen 1080i or 1080p HDTV without blurry interpolation - yes, they can do 720p very nicely and sharply with 2x2 double pixels for each 720p pixel, but well, you're not buying this kind of super display to watch 720p video, which many much

Interpolation of DVD and divx on a 1024x768 screen is fine, thanks. Don't they think a PC monitor would be used on a PC?

also, moving to 150 or 200dpi.. this will require vector based independant GUI such as in Vista.
other thing .. ultra high res at 48 or 50Hz on dual dual DVI link no less.. there really is something wrong. Better to wait for the successor of the ridiculous bandwith starved DVI.

 

[Xmas]

The smaller the pixels, the better does interpolation look even if you can't just double the pixels. High-Res displays are long overdue, and so is vector based GUI.

 

[soylent]

I don't think it will. Since MSAA + high quality AF is MUCH cheaper for the performance improvement it gives over increasing the resolution.

Texture resolution and triangle density of vertices needs to increase drastically before it makes any sense to increase resolution drastically.

As soon as you give game developers more performance, they will take it. Don't expect to play new heavily 3d oriented games at insane resolution any time soon.

But I'm all for monitors with much higher DPI. I sit half a metre from my monitor at most. I don't ever see myself wanting more than about 20 inch.(...and I don't see myself ever wanting an LCD for gaming. And yes I'm aware that they have gotten better. And no I still wouldn't use one for games.

60-70 Hz refresh rate is poor; the black level is still pretty bad; the price/quality ratio is still much worse than CRTs; the aspect ratio of higher res LCDs is annoying; the sharpness of pixels makes aliasing unnescesarilly apparent(slight interpolation between pixels on CRTs looks MUCH better to me); only the expensive monitors use lancoz/bilinear for scaling up images if you aren't in native res; the viewing angle dependence is too large on monitors in my price range; the gamma curve on LCDs in my price class is often non-standard which makes games look different from what they were intended.

A HDR LCD monitor with 4:3 aspect ratio, sane price, at least 100Hz refresh rate, bilinear /lancoz upscaling and at least 1600x1200 res is what it would take to change my mind about LCDs).

 

[Albuquerque]

A HDR LCD monitor with 4:3 aspect ratio, sane price, at least 100Hz refresh rate, bilinear /lancoz upscaling and at least 1600x1200 res is what it would take to change my mind about LCDs).

I can only assume you meant to type 10ms response time versus 100Hz refresh... There is no such thing as "refresh" on an LCD; liquid crystal display elements are "constant on" components. A CRT requires a "refresh" hit with the electron gun to keep the phosphors glowing, and lower refresh rates cause noteable flicker because the phosphors lose their "glow" before the next swipe with the electron gun.

Further, the items you just described really don't solve the horrible black-level issues, which is my biggest gripe by far on current panels. I'd like to add "multi-element variable level LED backlight" to your list, so that areas that are truly black can get truly no light behind them. Essentially I'd like to see the HDR LCD displays that were talked about many months ago using a hexagonal LED "grid" behind the panel to produce the light, which basically held a low-resolution gamma map of of the framebuffer used as the brightness level for the individual LED's.

 

[Warmonger]

My Dell Inspiron 9100 has a 15.4", 1920*1200 screen. By my calculations, that works out to approximately 147 DPI. Clearly the technology already exists for 150 DPI LCD monitors. So why is it that standalone LCD resolution is so much lower than something I can get on a laptop? Cost doesn't seem to be a major issue, since the upgrade from the next lower resolution cost about $400 at the time (I think it was 1280*800, but it's been a while so I can't say for sure), and that even included a 64MB video RAM upgrade.

 

[hughJ]

I can only assume you meant to type 10ms response time versus 100Hz refresh... There is no such thing as "refresh" on an LCD; liquid crystal display elements are "constant on" components. A CRT requires a "refresh" hit with the electron gun to keep the phosphors glowing, and lower refresh rates cause noteable flicker because the phosphors lose their "glow" before the next swipe with the electron gun.

There would still have to be a Hz rating though for the monitor, as to how often it's able to receive frames from the videocard, no? So if you're running a 60hz LCD, you're going to be limited to 60 visible FPS.

 

[ChronoReverse]

Well, my 12ms LCD is running at a refresh of 76Hz which works out to just about 13ms so I suppose faster LCDs would support higher refresh rates.

 

[Bolloxoid]

There is no such thing as "refresh" on an LCD;

There still is the adapter refresh rate, that is, how often the display is able receive a frame from the display adapter. Many CRTs can do that at 100 Hz, most at least at 85 Hz on a decent resolution.

Most LCDs seem to be designed to work at 60 Hz, which a significant step backwards.

 

[Albuquerque]

Most LCDs seem to be designed to work at 60 Hz, which a significant step backwards.

Well then, "most" of the LCD's you're looking at are rated at ~17ms response times. I'm sure there will be frame-rate purists who "need" a framebuffer update every 10ms, I'm not one of them. And no, we're not going to start a flame war about how many scene updates per second the human eye can physically observe, because everyone is different.

Generally speaking, the technology behind LCD displays is chemical and as such there will be a limit as to how fast you can manipulate those pixels. If we can eventually get a "true" 8ms response time on LCD's, that should be pretty damned close to perfect in my opinion. And I'm not quite sure how much faster we can go; maybe 5ms at best? (WAG of course)

 

[bloodbob]

Generally speaking, the technology behind LCD displays is chemical and as such there will be a limit as to how fast you can manipulate those pixels. If we can eventually get a "true" 8ms response time on LCD's, that should be pretty damned close to perfect in my opinion. And I'm not quite sure how much faster we can go; maybe 5ms at best? (WAG of course)

Ehh of hand I thought the LCD used physical methods. The molecules are orientated by an electrical field. I.e they physical move rather then formation or breaking of bonds.

By applying small electrical charges to transparent electrodes over each pixel or subpixel, the molecules are twisted by electrostatic forces.

from wikipedia. So unless most capacitors have suddenly become "chemical" I'd say this is either an electrical or physical effect.

 

[Jabbah]

Well then, "most" of the LCD's you're looking at are rated at ~17ms response times. I'm sure there will be frame-rate purists who "need" a framebuffer update every 10ms, I'm not one of them. And no, we're not going to start a flame war about how many scene updates per second the human eye can physically observe, because everyone is different.

Response times and refresh rates are perfectly valid for LCD monitors and relate to different aspects of their performance. Response time is how quickly a pixel can change from one level to another. Refresh rate is how often all the pixels in the screen have their level set. LCD monitors still have both. You can have 25ms response time LCDs with a refresh rate of 72Hz. If you do the math 25ms should only be capable of 40Hz!

Lower response time do not have a direct bearing on the refresh rate of the monitor, they are desirable due to the elimination of effects such as ghosting and trailing. LCDs also do not need high refresh rates to combat flicker like CRTs due to the persistence of each pixel.

Edit (Lets reply to the thread topic):

http://www.theinquirer.net/?article=29655 Some discussion/prediction there of a move to 150dpi from 96dpi.
Would higher pixel density on monitors make FSAA less necessary?

Higher pixel density on a monitor the same size will allow you to run at higher resolution. So it makes AA less necessary in the same way as going from 1024x768 to 1600x1200 on a CRT which IMO still needs AA. In theory a high enough density would negate the need for AA but those kind of densities are a long way off, as is the hardware to drive them.

 

[Bolloxoid]

And no, we're not going to start a flame war about how many scene updates per second the human eye can physically observe, because everyone is different.

It's not about how many "scene updates" people can perceive, as if there were be some kind of a general limit on that. That is a wrong conceptualisation of the problem.

The problem is temporal aliasing in the display of movement, which is readily perceptible. Fast movement will always be aliased on computer displays, but there is less aliasing with faster frame rates.

 

[soylent]

I can only assume you meant to type 10ms response time versus 100Hz refresh... There is no such thing as "refresh" on an LCD; liquid crystal display elements are "constant on" components. A CRT requires a "refresh" hit with the electron gun to keep the phosphors glowing, and lower refresh rates cause noteable flicker because the phosphors lose their "glow" before the next swipe with the electron gun.

They don't need to be refreshed if the image haven't changed, but that is AFAIK how we do it, so they do have a refresh rate. It doesn't make sense to increase the refresh rate unless the response time is lowered so those are directly connected. 60 FPS is not enough and will never be enough without motion blur.

Further, the items you just described really don't solve the horrible black-level issues, which is my biggest gripe by far on current panels.

I thought the whole point of HDR displays was to have a separate grid of white LEDs as backlights which increases the dynamic range of the monitor drastically and adds some bloom for free.

 

[Diplo]

The problem is temporal aliasing in the display of movement, which is readily perceptible. Fast movement will always be aliased on computer displays, but there is less aliasing with faster frame rates.

But thats kinda academic as, at 60 FPS, you are not going to notice any aliasing when moving around and immersed in a game.

 

[Ailuros]

http://www.theinquirer.net/?article=29655 Some discussion/prediction there of a move to 150dpi from 96dpi.

Would higher pixel density on monitors make FSAA less necessary?

It won't make AA redundant, but it would help making some aliasing aspects less noticable.

 

[Frank]

My Dell Inspiron 9100 has a 15.4", 1920*1200 screen. By my calculations, that works out to approximately 147 DPI. Clearly the technology already exists for 150 DPI LCD monitors. So why is it that standalone LCD resolution is so much lower than something I can get on a laptop? Cost doesn't seem to be a major issue, since the upgrade from the next lower resolution cost about $400 at the time (I think it was 1280*800, but it's been a while so I can't say for sure), and that even included a 64MB video RAM upgrade.

Obviously, as I'm sure you know, high res panels are limited by the readability, as there is yet no good way to increase font sizes in Windows, without having stuff invisible outside dialogs and other windows. Even the configuration pages from your GPU aren't acessible with large fonts, as you cannot click the "OK" button on them.

 

[Xmas]

Obviously, as I'm sure you know, high res panels are limited by the readability, as there is yet no good way to increase font sizes in Windows, without having stuff invisible outside dialogs and other windows. Even the configuration pages from your GPU aren't acessible with large fonts, as you cannot click the "OK" button on them.

I have to strongly disagree here. I'm using 120dpi in WinXP (for a 128dpi screen) and I very rarely have problems with dialog boxes that are too small. High-res displays are not limited by the readability, they massively improve it.
Which GPU config pages do you mean? I have no problems with the driver panel.

It won't make AA redundant, but it would help making some aliasing aspects less noticable.

I wonder if at some point it would make sense to output a multisampled framebuffer directly to the screen to keep the processing requirements for high-dpi monitors reasonable.

They don't need to be refreshed if the image haven't changed, but that is AFAIK how we do it, so they do have a refresh rate. It doesn't make sense to increase the refresh rate unless the response time is lowered so those are directly connected.

That is not entirely true. It does make sense to increase the refresh rate even when the response time is high. Because it means the pixels can switch earlier.