Digital Foundry Article Technical Discussion Archive [2015]

[Scott_Arm]

I think temporal filtering has to do with what sebbi said about the MSAA trick they were experimenting with. You can read more here. I might be wrong though.

It's not the same as the method sebbbi talked about.

 

[Shortbread]

Image quality is typically a pretty cut and dried affair but we see an interesting trick employed here that enables stable performance with a minor compromise to image quality. At its core, the PS4 version operates at 1080p while the Xbox One is 900p - but that's not the whole story. Ubisoft makes use of a "temporal filtering" feature that has a pretty interesting impact on the game.

Ok, I got this...

Essentially, this feature renders the game with half the number of pixels on each axis with an ordered grid MSAA pattern before reconstructing the image to match the final output. This is then coupled with a post-process temporal anti-aliasing solution to minimize artefacts in motion. So, at 1080p, we're technically seeing 960x540 with 2x MSAA.

So this "temporal filtering" is rendered at a lower resolution, then mixed/combined with 2x MSAA, and lastly upscaled to meet the native render of the game (PS4/1080p)? Correct?

Interestingly, it would appear that the image is processed before being upscaled on Xbox One resulting in blurrier HUD elements and menu text.

So the native game render (XB1/900p) is processed first, then the temporal filtering and 2x MSAA combination is applied afterwards? Correct? If so, why the different arrangement choices between the two (PS4/XB1)?

Edit: After re-reading this particular section I'm just lost. This IMHO, just sounds like a more updated/advanced version of Temporal Reprojection with a more complex combination of post-processing (temporal filtering) and AA solution (2x MSAA), on achieving the needed IQ.

 

[Globalisateur]

Avoid at all cost PAL versions of PS2 games emulated on PS4. Digital foundry tested the US version of San Andreas and discovered the game runs without frame-pacing issue at a very solid and smooth 30fps when the PAL game runs with constant judder.

Apparently all PAL PS2 games (those that probably were running at 50hz on PS2) run emulated on PS4 at 50hz and then are interpolated to 60fps causing frame-pacing issue and a constant judder.

but much of the judder we encountered is actually a result of the frame-blending, registering to our eyes (and our analysis tools) as unique frames when in fact they are simply the interpolated results of two images

http://www.eurogamer.net/articles/digitalfoundry-2015-grand-theft-auto-san-andreas-face-off

If you want to buy US PSN games while living in Europe, it's really, really easy (I did it to buy US only themes recently): http://www.nowgamer.com/ps4-how-to-buy-us-digital-psn-games/

Seriously how dare they charge us 15€ for those wrecked games?

 

[London Geezer]

And that old 50/60Hz goblin rearing its ugly head again, after all these years of peace.

 

[Shifty Geezer]

But for non English speakers wanting native language, they need PAL version. Can you force PS4 to PAL output?

 

[Deleted member 11852]

But for non English speakers wanting native language, they need PAL version. Can you force PS4 to PAL output?

Nope, you can select resolution and colour depth but not display frequency.

 

[hesido]

Sony surely can provide a native 50hz output.

They won't, though.

 

[London Geezer]

I think there were problems with 50Hz DVD playback at launch but I'm not sure they're still there.

 

[Globalisateur]

http://www.eurogamer.net/articles/digitalfoundry-2015-rainbow-six-siege-face-off

...so basically quarter resolution with MSAA and temporal fore reconstruction, apparently.

Essentially, this feature renders the game with half the number of pixels on each axis with an ordered grid MSAA pattern before reconstructing the image to match the final output....So, at 1080p, we're technically seeing 960x540 with 2x MSAA.

This is bugging me. Shouldn't it be 4x MSAA?

 

[rekator]

But for non English speakers wanting native language, they need PAL version. Can you force PS4 to PAL output?

Or give the 60Hz version to EU, all HDTV can output 60Hz.

 

[London Geezer]

^^ this

 

[Shifty Geezer]

Or give the 60Hz version to EU, all HDTV can output 60Hz.

What about European languages?

 

[Clukos]

Edit: Looks like they removed a bunch of shadows from Ps4/PC version to achieve that "boost"

Image from gaf

 

[DrJay24]

One screenshot is not evidence of some global downgrade. It's clear from DF video that shadows are preset and the graphics look to be the same everywhere but that one room. Smells like a bug. They obviously did some optimization since the outdoor part in the video, which looks identical, performs much better as well.

 

[Deleted member 11852]

Digital Foundry: Fallout 4 patch 1.02 boosts PS4 performance
Bethesda brings us closer to 30fps - but is it stable?

As things stand, the improvement is clearly tangible, even if the frame-rate still isn't 100 per cent ideal. A flat reading at around 20fps creeps in once we trigger explosives in the sewers, while the high-rises of the factory plant still take a toll on PS4's frame-rate.​

Fire and explosions are by far the most prevalent reasons for the frame rate nose dives on PS4. No matter what you are doing, if you add an explosion and sometimes just a little fire, the frame rate will drop. This is only observational evidence but I'm glad I'm not playing a heavily explosive focused build!

 

[Allandor]

What about European languages?

At least all european HDTVs are 50Hz capable, else they couldn't display the current non-hd TV program. So sony should at least be able to output 50Hz if it is a PAL game. On the other side, I would want the NTSC-Versions of a game, because PAL versions often just run slower to get to 50 Hz (25fps). Xbox one can output something @50Hz, so why shouldn't PS4 do the same thing?

 

[tuna]

Most European hd programming is 50hz.

 

[Deleted member 11852]

Most European hd programming is 50hz.

I don't disagree but have an interest and woulkd like to know the source for this. My experience is that there is an awful lot of 25Hz 1080p programming but very little 50Hz 1080i prorgramming these days.

 

[Shortbread]

Digital Foundry: Fallout 4 patch 1.02 boosts PS4 performance
Bethesda brings us closer to 30fps - but is it stable?

As things stand, the improvement is clearly tangible, even if the frame-rate still isn't 100 per cent ideal. A flat reading at around 20fps creeps in once we trigger explosives in the sewers, while the high-rises of the factory plant still take a toll on PS4's frame-rate.​

Fire and explosions are by far the most prevalent reasons for the frame rate nose dives on PS4. No matter what you are doing, if you add an explosion and sometimes just a little fire, the frame rate will drop. This is only observational evidence but I'm glad I'm not playing a heavily explosive focused build!

I'm starting to wonder how the Havok Physics engine is implemented across certain game engines. Are some developers relying strictly on the CPU to run physics duties (ragdolls, collision detection, clothes simulation, debris/particles, etc...)... or strictly GPU computing... or a combination of both. It seems lately, games that use the Havok engine (Fallout 4, Just Cause 3, etc...) are having certain amount of performance issues on PS4/XB1.

I think/believe Sucker Punch used a lot more of the GPU side when it came to using the Havok engine in Infamous Second Son... such as particles/debris/collision and possibly some other physics related task. And from what I remember playing, explosions/debris and so-on, didn't effect the framerate at all (or enough to warrant it as an issue of cause).

 

[Shifty Geezer]

I don't disagree but have an interest and woulkd like to know the source for this. My experience is that there is an awful lot of 25Hz 1080p programming but very little 50Hz 1080i prorgramming these days.

I presume Tuna means 50 Hz display rate material. Whether recorded at 25 fps or 50, the TVs tune to 50 Hz and could support 50 Hz game output if provided. Or putting it another way, there's very little 30/60 Hz content in Europe warranting a 60 Hz TV, and it's only computer use that benefits (which then displays PAL content in judder-o-vision).