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...but entirely deterministic! ;-)
OK, so check this craziness out:
http://www.youtube.com/watch?v=duy8s8C7-Uc
http://www.youtube.com/watch?v=58_s6r7PaKo
Each video is approximately 5 hours of computer time. And trust me, when
you watch this full-screen in high resolution, it looks insane! :-D
Pitty YouTube doesn't permit such things. (The file I uploaded was about
35MB, encoded with "H.264". I might put it online somewhere else for you
folks to enjoy...)
So, let me know what you think. :-D
PS. I still need to fix the rendering program. I wrote it while at work,
and it worked OK, but was rather inflexible and brittle. So when I got
home, I wrote it again. But for some reason, the version I wrote at home
is about 10x slower - and I can't figure out why! o_O
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> http://www.youtube.com/watch?v=duy8s8C7-Uc
> http://www.youtube.com/watch?v=58_s6r7PaKo
Very nice.
> Each video is approximately 5 hours of computer time.
You're just begging me to try and write a GPU version that runs at 100fps
aren't you :-)
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Invisible <voi### [at] dev null> wrote:
> Each video is approximately 5 hours of computer time.
I wonder how much faster it would be if it was properly implemented in
a *real* programming language... ;)
--
- Warp
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scott wrote:
>> http://www.youtube.com/watch?v=duy8s8C7-Uc
>> http://www.youtube.com/watch?v=58_s6r7PaKo
>
> Very nice.
Thanks.
YouTube hardly does it justice, but you can see what I mean about the
way it moves, eh?
>> Each video is approximately 5 hours of computer time.
>
> You're just begging me to try and write a GPU version that runs at
> 100fps aren't you :-)
If you think you can do adaptive RK4 numerical integration of a few
thousand particles at realtime speeds, be my freakin' guest! ;-)
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Warp wrote:
> I wonder how much faster it would be if it was properly implemented in
> a *real* programming language... ;)
Is that a challenge? :-P
Do you know how to numerically integrate a physical simulation? ;-)
You're welcome to try if you like...
You're not totally wrong though: When I initially implemented this, I
discovered, to my astonishment, that converting the state of the system
into an image took vastly longer than all that complicated Runge-Kutta
numerical integration stuff. Which, obviously, is absurd.
On closer investigation, the program was spending 80% of its time in one
function: floor. Looking at the source code, I discovered that floor is
implemented by converting a floating-point double into an
infinite-precision rational and then converting that into an integer.
Like, WTF?
It seems that while *most* numeric operations are very fast, one or two
of the more unusual ones are jaw-droppingly slow.
Anyway, I replaced floor with a direct call to the compiler's low-level
internals library and now converting to an image is near instantaneous.
(Like you'd expect!) It takes longer to suck the data off disk than to
process it.
Now if I could just find a way to make the integration go faster... ;-)
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http://blog.orphi.me.uk/archives/365
Some more background for any interested souls.
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>>> Each video is approximately 5 hours of computer time.
>>
>> You're just begging me to try and write a GPU version that runs at 100fps
>> aren't you :-)
>
> If you think you can do adaptive RK4 numerical integration of a few
> thousand particles at realtime speeds, be my freakin' guest! ;-)
I wonder how fast it would be in C++ :-)
Are the three attractors just applying a 1/r^2 force on each particle?
What resolution are you running this at? "a few thousand" sounds like 64x64
or something.
When I get time I will give it a shot, but it might not be a while I'm
preparing today and tomorrow for two weeks of business travel.
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>> If you think you can do adaptive RK4 numerical integration of a few
>> thousand particles at realtime speeds, be my freakin' guest! ;-)
>
> I wonder how fast it would be in C++ :-)
Go ahead, knock yourself out. ;-)
> Are the three attractors just applying a 1/r^2 force on each particle?
Nope. Currently just 1/r for the "magnets", plus an r force for "gravity".
> What resolution are you running this at? "a few thousand" sounds like
> 64x64 or something.
It's 1,728 x 972 pixels. (And one particle per pixel, obviously.)
I *said* YouTube doesn't do it justice. ;-)
> When I get time I will give it a shot, but it might not be a while I'm
> preparing today and tomorrow for two weeks of business travel.
Yeah, sure, whatever. It's pretty fun stuff to play with though...
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>> What resolution are you running this at? "a few thousand" sounds like
>> 64x64 or something.
>
> It's 1,728 x 972 pixels. (And one particle per pixel, obviously.)
Ah ok, so "a few" means "over 1600" :-)
> I *said* YouTube doesn't do it justice. ;-)
I can well imagine.
> Yeah, sure, whatever. It's pretty fun stuff to play with though...
Also I can imagine, this is the sort of stuff I like playing about with too.
I wonder if the plane seat will have a power socket for my laptop ... hmmmm.
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That is brilliant! Well done you. :)
Add this to the end of the URL: &fmt=22
Not only hi-res, but bigger too... ;)
~Steve~
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