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[PompiPompi]

So I implemented motion blur. You can see it here:
http://youtu.be/2cC_LjdvAes

I also added a machine gun with recoil which you cannot see in this video.
The big issue is that if I am at an enemy character, the character is all sharp and clear. But if I shoot, I have recoil and the view moves and thus there is motion blur and the characters gets a bit blurry which is what the motion blur is supposed to do.
However, this makes it annoying for the eyes to focus and track on the character you are shooting because it becomes blurry for an instant.
How do other games do motion blur in this repsect?
I admit I didn't play a lot of high end FPS games lately?

[Liosan]

You could intensify the motion blur around the edges and ease it in the center; that way whatever the player is looking at will remain more or less visible.

Liosan

[PompiPompi]

Yea, I actually thought about doing that.
But then if I have an object wooshing in front of the camera, like a flying boulder it will be less impressive? Not sure.

[Danmark]

Haven't noticed how contemporary games handle it.

I assume you mean the recoil rotates the view? That's obnoxious in itself, and doesn't make sense, because (reasonable) firearm recoil isn't enough to overcome human eye tracking IRL. Even the translational impulse part should be subtle, since we stabilize the head pretty effectively while shooting.

It'd help if you showed us a video with the gun.

[Will Vale]

FPS recoil often does stuff to the gun model (but not the view) and increases the size of the scatter window for your shots rather than actually kicking your camera around.

FWIW your motion blur looks a bit too strong (and undersampled) in the video - you might want to try fixing the upper length of your motion vectors so the blur is subtler and smoother.

Michiel's presentation here has a brief but useful outline of what we did in KZ2/KZ3, maybe that'll be of interest? The one you want is "The PlayStation®3’s SPUs in the Real World: A KILLZONE 2 Case Study"

http://www.guerrilla-games.com/publications/

HTH,

Will

[PompiPompi]

I was told from another guy who worked on an AAA title that there is an issue with instant motion. You don't want to have motion blur for somethign that moves instantly for only a few frame, but rather for more continous motion.
I think that will improve it.
Also compacting the motion blur could help, as you suggested.

The recoil that moves the gun is I think a really good design choice for recoil. I hate scattering, because it basically means throwing your bullets randomly around and that makes it impossible to hit from a certain distance.
With the motion recoil you can still hit far away if you just hold your gun still.

Games that have motion recoil for instance are BF1942 and maybe other BF games.

Edit: I have also seen the motion blur effect for KZ, and it's not very impressive :/
But maybe laso not murdering player eyes.
For instance an image of motion blur I did:

[moi]

I don't think motion blur brings anything interesting to game, and if you think about it it's a rather dumb concept.
It's the same as lens flares.

[PompiPompi]

It looks cool.
Your screen is also only 2D, is that dumb too?

[Sam]

I think the point is that many graphics effects mimic how a camera sees the world rather than how a human visual system sees the world. Lens flare is the most obvious example as it's a phenomena that simply cannot occur in a healthy human eye.

Motion blur is less certainly a camera-only thing, as anyone that's looked out the side window of a fast moving car can tell you. But the motion blur effect in games (and in video captured by a camera) is of a quite different form that that experienced by a human eye in normal experience.

The main difference is in how the eye moves compared to a camera (either a camera in a game or used to record a video). As I'm sure you know our eyes move in rapid and frequent saccades, shifting the view's focus extremely quickly from one object to another. If film cameras did this it would be disorientating to the viewer, so they either make far slower panning motions if they want to show the viewer around a scene or cut between different shots. Even the most over the top rapid cuts in action films occur less frequently than a person's normal saccadic scanning of a scene.

Importantly we do not experience any blurring during the eye's saccades. So if I look around a room at no point do I experience my image of the room as being blurred. Try to look around a room in a video game with motion blur enabled and everything's a blurry mess unless I keep stopping the camera.

Similar differences occur with moving objects. A camera placed at the finish line of the 100m sprint will show a blurred streak as Usain Bolt inevitably wins. A human stood in the same place will find their eyes effortlessly tracking the motion of the runners so that they appear perfectly clear while the background is blurred by the speed. But (and this is important!) with the tiniest thought they can shift their focus to the background and see that with clarity.

In conclusion:
When we do see motion blur it is far less intense than that seen with a typical 24fps movie camera (incidentally please don't try to understand the workings of our vision in terms of frames per second, the concept doesn't apply).
We are able to extremely easily shift our attention between objects in a scene such that we can eliminate motion blur at will.
The result is that our visual experience of the world is one where motion blurring is almost entirely absent. If you include motion blur in a video game, do it knowing that you are simulating how a camera sees the world, not how a person does.

P.S. For very similar reasons, depth of field effects in games are silly. It's true that at any moment my eyes are focused at a particular depth, but the instant that I think of looking at an object in the world it is brought into crisp focus. As with motion blur the result is that I experience the whole world as being in focus. Similarly I experience the whole world as being in colour, even though it can only be detected in the central part of my visual field. Thankfully games haven't started desaturating everything but a central circle and claiming it as realistic.

[PompiPompi]

First, there is the cool\screenshot\hype factor. Which is also something to consider. I will also make all this stuff optional. But even then, I will try to make it pleasent rather than make the player blind.
Regarding motion blur you are right about the human vision. That is a good explaination to why instant motion blur is bad.
However, it's still nice to have motion blur for quite fast objects. Like a boulder flying in the air, or looking outside the window of a train.
About DOF, I agree it's quite problematic. Especially if your eyes focus on something the game decides is out of focus.
I don't mind simulating cameras instead of eyes though. What works out in the end.
I have no fetish about beating the AAA companies with their evil ways of simulating cameras instead of simulating the human eye.
By the way, I think the human eye does haev a type of motion blur when you move your eyes really fast. You don't see things blurry, you actually become blind to a split second. That is what I was told.

[Evan Balster]

http://en.wikipedia.org/wiki/Chronostasis

You become blind but you don't notice it.  Thus you perceive no blur.


Anyway, I think Sam's argument (which I agree with) is that you shouldn't simulate the human eye, but you also shouldn't motion-blur camera movement.  Something I'll chip in is that if you're doing motion blur, you shouldn't bother with framerates over 30 hz, since you already have the smoothness of motion covered.  (Assuming your motion blur is believable in some regard.)

[JakobProgsch]

Motion blur helps against temporal aliasing. But sadly most games use it as an "effect" which makes it really obvious and annoying. The proper way imho is to only use it to integrate between frames. That way the effect is barely visible but it makes the movement smoother.

[moi]

1-motion blur is not "cool"
2-in most moderns PCs it's unnecessary because either the monitor is a CRT and the FPS is so fast that blur happens naturally , or it's a LCD and blur+latency makes the picture look like a giant mess
3-it's a performance hog

[JakobProgsch]

2-in most moderns PCs it's unnecessary because either the monitor is a CRT and the FPS is so fast that blur happens naturally , or it's a LCD and blur+latency makes the picture look like a giant mess

Depending on what exactly you do it can still help. I had the case where the graphics were very "vectory" and with fast movement you essentially get a bunch of "sharp" images overlaid on top of each other instead of them being "smeared" along the movement. Adding motion blur (only to interpolate between frames) just made it look smoother without being that blur-in-your-face-effect.

[Schoq]

Something I'll chip in is that if you're doing motion blur, you shouldn't bother with framerates over 30 hz, since you already have the smoothness of motion covered.

Lower framerate looks worse no matter how much you blur it. And at higher framerates the image can remain more clear in motion while still adequately tweened with blur.