Motion blur

[hang3r]

I guess you could also use GL Shading Language to do motion blur, but as a lot of people don’t have hardware that is capable of this...

[Jonathan]

hang3r (before my previous post, which was by the way directed at Lucifer): That article is very confusing. As I understand it the author wants trails and not type of the motion blur we want. However, it is possible to use textures to do it, which may be faster if there's better hardware support. Unfortunately that's not a quick hack like the few lines above.

[hang3r]

Yes i agree,yes you could just stick a textured plane in front of the screen that is of the last frame with an alpha value, i was simply saying that there are alternatives.

EDIT: tyred ignore me

[Jonathan]

I tried playing online at 320x240 with 4x motion blur. That, combined with 15-20 fps, is sort of unplayable.

[hang3r]

I just with the accumulation buffer and got about 5-10 fps @ 320x240 rendering 4 times, heh

[Jonathan]

I played with the source a bit more, and managed to make a movie. Just put the segments together

Code: Select all

$ gunzip -c motionblur2.mp4.0.gz > motionblur2.mp4
$ gunzip -c motionblur2.mp4.1.gz >> motionblur2.mp4
$ gunzip -c motionblur2.mp4.2.gz >> motionblur2.mp4

and watch it. Sorry that it's so big, but I don't have another portable way (I hope this is one - please verify) that looks good. It still doesn't.

Edit: Yes, I know I changed the "wrong" timer, but actually it is more playable at extremely low speed.

[Z-Man]

It seems like the accumulation buffer is not well supported on consumer grade hardware. It should be possible to fake the accumulation buffer effect with the same techniques that are suggested for the "Motion Trails" effect in the document hang3r linked to. BTW, the confusion about what motion blur actually is probably comes from the game industry using it for exactly the motion trails effect. Either that or a faked motion blur that only works in racing games where they just blur out the final rendering in radial direction.

I'd also like to note that on a CRT with sufficiently high refresh rate, motion blurring is largely pointless. The reason is that the eye follows the motion of objects, and since on a CRT the objects typically flash for a very short time (compared even to the refresh rate), the eye following the moving object will see it perfectly sharp (as in reality) and flickering unnoticeably. Adding motion blurring here only blurs the object.
On a LCD, where the image is displayed constantly over the whole cycle, things are different; there a little blurring can improve the visuals considerably. Of course, the LCD will add its own blurring all by itself

[Jonathan]

It seems like the accumulation buffer is not well supported on consumer grade hardware.

As if you need to mention that after us getting extremely low framerates.

It should be possible to fake the accumulation buffer effect with the same techniques that are suggested for the "Motion Trails" effect in the document hang3r linked to.

Yep.

On a LCD, where the image is displayed constantly over the whole cycle, things are different; there a little blurring can improve the visuals considerably. Of course, the LCD will add its own blurring all by itself

Trails effect, with only one per frame? BTW, my LCD is pretty quick. I once made a screensaver that draws 8 colored bars (in all colors possible in 1 bit per channel RGB), and moves them one bar per frame (1/60th second). The bars clearly kept their own colors when I ran it. I'll see if I can still find it.

Edit: I lost the source. The screensaver itself is still on my disk.

[hang3r]

Something does seem rather strange about the poor fps, i have a Geforce 4 ti 4200 overclocked a little, im sure the accumulation buffer isnt to blame for this? but i cant see why its so poor

[Z-Man]

Emphasis:

It seems like the accumulation buffer is not well supported on consumer grade hardware.

The accumulation buffer is not terribly sophisticated technology, but since it's not used in games, it's not supported well on gamer's cards. Of course, since it is not supported well, games don't use it AFAIK, when you buy a professional 3D card, one optimized for CAD stuff, you get a fully accelerated accumulation buffer.

[hang3r]

/me goes out to buy a nvidia quadro fx just so he can play armagetron with motion blur

[Tank Program]

The stuff with the motion blur looked pretty sweet on my display from the video. I shall have to try the source mod...

[Tank Program]

Haha, it hates me, look @ this:

[Jonathan]

Nice.

[hang3r]

The two frames per second tells the story......