Another good rule of thumb (for now): if you can't actually see the effect, there's better ways to utilize your processing power.Originally Posted by Korval
Another good rule of thumb (for now): if you can't actually see the effect, there's better ways to utilize your processing power.
The details are trivial and useless;
The reasons, as always, purely human ones.
it's not an effect, it's what's required to simulate natural optics.
No. The purpose of realistic motion blur is to reduce or eliminate the undesirable strobing effect. You're not supposed to see the blur in and of itself.Another good rule of thumb (for now): if you can't actually see the effect, there's better ways to utilize your processing power.
-Suncho
Just as with many other effects: As long as you DON'T have the processing power, you exaggerate the effect, such that people see, what cool graphics their PC is able to do. Once hardware has evolved enough to be able to always utilize the effect, you can tune it down so much, that it is subtle and realistic. Then it usually looks MUCH better, but not everyone will notice that it is actually their. So, eating up all the available processing power forces you to make an effect clearly visible, otherwise dumb customers will complain, that they don't know why your app is so slow.
Jan.
GLIM - Immediate Mode Emulation for GL3
Thanks Jan; that's why I specifically said "for now" >
If simulating natural optics is your primary goal, then why are you wasting your time with rasterizers? >
The details are trivial and useless;
The reasons, as always, purely human ones.
As we're rendering on a 2D surface, it's things in recorded videos that we try to put in games, right? First were lens-flares, then bloom, then simplistic DOF, then simplistic MBlur. Initially in games these effects were over-exaggerated for the "coolness" factor (and we gamers love it initially), then made more subtle - so that becomes more realistic.
But if you look closer in videos, you can see motion-blur almost everywhere. Moreover, if you just move your hand, the mblur is clearly visible (under sunlight or heated-wire lamps). If you rotate your head not too slowly, and not move you eyes, it's also visible. (if you move your eyes, which we usually do when turning to look somewhere, the brain dampens the mblur tenfold in one way or another).
Oh well, the above things are all of my personal experience and research, and I can't rule-out I have some strange vision or perception.
Meanwhile, DOF can get in the way in games. The gamer will often want to focus on some specific object - but the required input-controller for that will never be available (who wants a HD camera to monitor one's pupils nowadays). So, only RPGs and other camera-looking-down games can safely use it. Maybe some similar limits are present for using MBlur? Like how one's vision dampens MBlur tenfold when moving one's eyes - but expects full blur on keeping the rotation angle (oh well, at least here we can use the mouse/Right-Stick axis as input).
No, your eye / brain does not experience any motion blur. What you mean is simply the fact, that the brain can't process so much information in a short time, so you don't notice any details anymore. However, there is no "motion blur" in the strict sense of the word, since your eyes are capable to send many hundreds of different signals to your brain per second. Your brain starts ignoring those signals much earlier, than the "sampling rate of your eyes" becomes the limiting factor.
"Motion blur" as we know it, however, is indeed the problem, that your sampling rate is too low AND that you sample over a whole time-frame. In films this happens, because you usually sample at 25 Hz and each sample takes 1/25th of a second. That means all the movement during that time-frame is captured on film and smears the image. Note, that this is something entirely different, than what happens, when you simply move your head quickly.
In games, on the other hand, you do have a low sampling rate, but also you sample at a fixed time, which results in clear and sharp images, at low speed, such that the brain does interpret it as "moving" but is actually capable to notice the sharp differences.
The perfect solution would be really simple: do what nature does, present hundreds of perfectly sharp images per second to the viewer. At 1000 frames per second it will look like the real world. However, sadly that's not possible, so we revert to the second best option: do what films do, sample over an entire time-frame (well, approximate it as good as possible).
I do have yet to see a technique for motion blur, that convinces me in quality AND implementation. All methods i know so far either make the effect too extreme (e.g. accumulation buffer, where you even get motion-blur, when you simply turn around) or they only work on certain objects under certain conditions (and are usually much more difficult to implement).
Jan.
GLIM - Immediate Mode Emulation for GL3
Yes, and that is precisely why I hate every implementation of the following in games:Just as with many other effects: As long as you DON'T have the processing power, you exaggerate the effect, such that people see, what cool graphics their PC is able to do.
- HDR
- Motion Blur
- Lens Flare
- Motion Blur
- Depth of Field
- Bloom
- Motion Blur
These are all gigantic signposts that say, "Hi. I'm an amateur graphics programmer who doesn't know what he's doing!"
The answer is simple: if you can't do something right, don't do it at all. If you aren't committed to real motion blur, don't bother with hacks. Introducing noise into an image is the worst thing you can do.So, eating up all the available processing power forces you to make an effect clearly visible, otherwise dumb customers will complain, that they don't know why your app is so slow.
The first thing you need to do motion blur correctly (besides the willingness to eschew any/all hacks and actually render at a high framerate) is real HDR. You can't do motion blur correctly if you're just alpha blending non-HDR 24-bpp frames. You have to commit to using HDR everywhere, always (except the HUD), and correctly. No linear alpha-blend type stuff anymore; it's all got to be real additive light accumulations.I do have yet to see a technique for motion blur, that convinces me in quality AND implementation.
These are all gigantic signposts that say, "Hi. I'm an amateur graphics programmer who doesn't know what he's doing!"
LOL
Well actually I am the amateur here
But Mars, please elaborate further
Jan: yes, we can never please the eye ^^". But at least we can try approximating some things to look like _video_. RPGs and ingame videos can look better with mblur, imho. I think it helped the cutscenes in MGS4 a lot, but I could be mistaken.
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