A comparison of motion blur implementations *spawn

[Clukos]

I mean: what is temporal reprojection? Just use a few old frames and interpolate new ones? Can't be that primitive and would not be called reprojection.

So what is temporal reprojection (in a mathematical sense?)

According to Guerrilla: http://www.killzone.com/en_GB/blog/news/2014-03-06_regarding-killzone-shadow-fall-and-1080p.html

Temporal reprojection is a technique that tracks the position of pixels over time and predicts where they will be in future. These “history pixels” are combined with freshly rendered pixels to form a higher-resolution new frame. This is what KILLZONE SHADOW FALL uses in multiplayer.

So, in a bit more detail, this is what we need for this technique:

We keep track of three images of “history pixels” sized 960x1080

The current frame

The past frame

And the past-past frame

For each pixel we store its color and its motion vector – i.e. the direction of the pixel on-screen

We also store a full 1080p, “previous frame” which we use to improve anti-aliasing

Then we have to reconstruct every odd pixel in the frame:

We track every pixel back to the previous frame and two frames ago, by using its motion vectors

By looking at how this pixel moved in the past, we determine its “predictability”

Most pixels are very predictable, so we use reconstruction from a past frame to serve as the odd pixel

If the pixel is not very predictable, we pick the best value from neighbors in the current frame

On occasion the prediction fails and locally pixels become blurry, or thin vertical lines appear. However, most of the time the prediction works well and the image is identical to a normal 1080p image. We then increase sub-pixel anti-aliasing using our 1080p “previous frame” and motion vectors, further improving the image quality.

You can also see that in the link i posted above in his "rendered pixels" comparison and the final result. Regarding AA, there was a GDC presentation yesterday about this, maybe you can find it

http://schedule.gdconf.com/session/temporal-reprojection-anti-aliasing-in-inside

Temporal Reprojection Anti-Aliasing is a spatio-temporal post-process technique, where fragments from the most recent frame are correlated with fragments from a history buffer through reprojection. By carefully jittering the view frustum, and by making sensible choices for when to accept or reject a history sample, this technique can produce images that are superior to the input in terms of information density, because the information in every fragment accumulates over time.

This talk will focus on Temporal Reprojection Anti-Aliasing in the context of INSIDE. It will touch on the process, the initial research, and the pleasant side-effects. Most importantly, it will discuss in-depth the individual stages of the implementation written for INSIDE, and how it deals with common problems such as disocclusion and trailing artefacts.

 

[Billy Idol]

Cool, thanks a lot.

 

[Egmon83]

The motion blur in Interstellar reminds me of the order. I wonder if we will ever witness a game with such graphical excellence ever again. It was no checkbox tech, like star citizen (which looks ugly as hell / extremely unpleasant), but rather carefully chosen effects which accumulate in the most visual stimulating package to date. RIP Ready at Dawn

Other games' motionblur are so messy and incorrect I can't even look at them anymore

 

[Clukos]

Cool, thanks a lot.

No problem :smile:

Seems like the slides for the presentation will be up today: https://twitter.com/codeverses/status/710864152131203073

Also source code if you wanna take a look at it: https://github.com/playdeadgames/temporal

Temporal reprojection specifically: https://github.com/playdeadgames/temporal/blob/master/Assets/Scripts/TemporalReprojection.cs

 

[Clukos]

Camera and object moblur in Quantum Break, direct feed images from Digital Foundry

Seems pretty good to me (look at the lamp in the background).

 

[MJP]

RIP Ready at Dawn

Uhh, we're still around you know. ;-)

 

[DieH@rd]

RaD announced they are switching to a PC for a bit, porting Order engine and making some VR project.

All of that is nice, but what I want is a sequel to Order [with expanded.... well everything].

 

[Egmon83]

Uhh, we're still around you know. ;-)

Sorry, for the misunderstanding. I meant "RIP the order" of course. Btw I absolutely loved the Order, every second of it. I played about an hour at a time, taking my time marvelling at the environments and listening to the excellent soundscape. The combat and the weapons were super also, especially the thermite rifle and the sound it makes when you spray the thermite. I really enjoyed the story as well.

The only thing I hated was the media reception. Kotaku or Eurogamer even went as far as creating a " you shouldn't pre-order the Order" article. Something which has never happened before in the history of videogames, even when they knew the actual bethesda or ubisoft game was broken and would be in the months following release.

I see The Order as a special wine which only few people can truly enjoy. Which is a shame because it is a rare masterpiece. And that includes the motion blur

I want a sequel as well! I really hope the game did well enough for you to warrant a sequel. Unless you guys hated working on it, in that case, I will cherish The Order forever but I hope for you guys I will never be president, because then there will be a The Order 1889 ;-)

 

[MJP]

Well thank you for the kind words guys.

Anyhow, to get this back on topic...the actual motion blur algorithm was based on Morgan McGuire's work, with a few last-minute optimizations that were inspired by Jorge's presentation from SIGGRAPH. So there's not really anything particularly novel in our implementation, but we did definitely spend quite some time on both the engineering and design/art side to make sure that the quality was consistent.

 

[Shifty Geezer]

Moved the human eye discussion here as milk was enjoying it.

 

[Globalisateur]

Interesting excerpt found in the Morgan McGuire's work, thanks @MJP :

Camera Parameters. When the camera tracks a fast-moving object, that object remains sharp and the rest of the scene blurs (figure 8). This is because the motion with which we are concerned is measured on the image plane, and is thus relative to the viewer’s own motion and orientation. Today’s games and film are rendered independent the viewer’s attention within the frame. The experience of viewing the rendered image differs from viewing the original scene with a naked eye if the camera and eye track different objects. This is perhaps one reason that film exposure times are much shorter than the frame display time–another is that moving objects simply look too blurry otherwise. Valve recommends using only 15% of the full-frame shutter and a maximum velocity of 4% of the screen width [Vlachos 2008]. All results in this paper were rendered with a 1/2 frame exposure to exaggerate blur for analysis. We speculate that with sufficiently robust and low-latency eye tracking, it might be desirable as future work to perform motion blur based on the viewer’s actual attention.

So some do recommend being reasonable with motion blur, even in films, because otherwise objects in motion would be too blurry. No kidding.

Aren't those recommended settings rather low? Do we know some specific settings used in some current games?

 

[Clukos]

Moblur in Uncharted 4 seems to be pretty good

In motion: http://gfycat.com/LastPlayfulFantail

 

[Globalisateur]

Moblur in Uncharted 4 seems to be pretty good


In motion: http://gfycat.com/LastPlayfulFantail

I vehemently disagree. First it's too strong (which is sadly usual for a 30hz game from Naughty dog), and secondly the motion blur itself doesn't keep enough information from the original pixels. It's what I call cheap.

Driveclub (RIP ) has a much, much better motion blur IMO. Compare how the leaves are motion blurred in Driveclub VS how the grass is blurred in UC4. The blur in UC4 is basically that: a cheap blur just for the sake of blurring it, you loose a great deal from the original information.

In Driveclub there is really a motion blur that is simulated. They call it "plausible motion blur" in my previous link. You can easily see the "direction" of the blur, and those directions are consistent with the direction of the camera. In the end it's much more sharp, even in motion. The judder is taken care of, while reasonably keeping some clarity from the original pixels.

For me the difference of quality between those 2 pics is super obvious. Apples vs peaches. Uncharted uses a cheap motion blur (and too much of it) when Driveclub uses a high quality motion blur with a lighter setting. Remember that I have taken the Driveclub pic a full speed, maybe 200 km/h VS maybe 50 km/h for UC4. But hey It's only a jeep. Even the cars in UC4 are cheap.

I get similar perceptual results when I compare motion blurs from Battlefront VS MGS5, both 60fps games. Battlefront is much better at keeping some information in the image. Even if Battlefront moblur is less good than Driveclub's, it's still better than MGS5 moblur.

 

[Clukos]

Ok, once again with the movie example. Another good one (Casino Royale this time)

Look at the foliage in the background in the last shot (on a very slow moving vehicle i might add), as I've said before, it boils down to i prefer X technique more when it comes to strength of the moblur applied and not the actual quality of the application. But i at least hope for your sake ND have a motion blur option in the menu

 

[Globalisateur]

Look at the foliage in the background in the last shot (on a very slow moving vehicle i might add), as I've said before, it boils down to i prefer X technique more when it comes to strength of the moblur applied and not the actual quality of the application. But i at least hope for your sake ND have a motion blur option in the menu

Lol so your feeble attempt to convince me (not enough moving green leaves in the last pic) was just a poor excuse just for the sake of posting the best looking Bond girl ever?

Not, wait you are right, this Green is indeed the best looking ever! You convinced me!

 

[Clukos]

Had to get one shot with Eva Green

 

[Clukos]

But i also made a point, motion blur use varies from game to game and even if we take a look at movies (which is what everyone tries to imitate in recent AAA games) it's hard to tell which technique is "best". Movies tend to blur the image a lot more than games do and it still doesn't look off or blury when watching a film (because of the density of information in focused areas i guess?). In any case, i'm perfectly fine with the current implementation in Uncharted 4, i think it looks great in motion.

 

[Globalisateur]

You made a point indeed and your posts are really showing where the problem IMO is in most people's minds. Motion blur and others effects like CA, DOF or grain filter in videogames are often used in order to imitate the look of movies.

But i also made a point, motion blur use varies from game to game and even if we take a look at movies (which is what everyone tries to imitate in recent AAA games it's hard to tell which technique is best. Movies tend to blur the image a lot more than games do and it still doesn't look off or blury when watching a film (because of the density of information in focused areas i guess?). In any case, i'm perfectly fine with the current implementation in Uncharted 4, i think it looks great in motion.

When it should only be used in order to remove the judder while, if possible, retaining some details from the original content. And we know it's possible to decently have both. I think that some developers only use motion blur in order to remove some judder (Driveclub, Battlefront) when others developers use it like a tool in order to have a filmic style (UC4, MGS5).

And it's indeed totally consistent with the tradition of those developers: Evolution / Dice was / is striving to do realistic games when Naughty Dog and Kojima are striving to do videogames that tend to look like movies, both structurally and with the artstyle.

 

[Clukos]

Uh...

How is that not like a movie? I don't think the line in that argument is as clear as you think it is.

How is that realistic

And U4 is not? I think we've already clarified that whatever doesn't properly track eye movement (position, depth, focus) isn't realistic by definition.

 

[Globalisateur]

The game itself has in fact a realistic artstyle. It's like you really are in the world that is depicted in the movies.

Battlefront is one of the most realistic game released so far this gen. I think the PSVR version will impress a lot of people. This game was meant to be ported to VR!