Plasma Pong

[Borodog]

This got zero play in OOT, and I have no idea why, because it is SO AMAZINGLY COOL.

Plasma Pong (http://www.plasmapong.com)

This is the classic game of pong embedded in a real-time computational fluid dynamics engine. Hold the left mouse button down to send out a jet of plasma from your paddle, or hold the right mouse button down to suck the ball into your paddle before releasing it with an explosive shockwave.

My record is level 20.

Also, be sure to play in the sandbox mode. Put it on particle mode (lower left corner) and inject a bunch of particles into the flow. In normal mode the left button "stirs" the velocity field, whereas the right button injects dye into the flow.

Oh yeah, make sure you turn vorticity on in the sandbox mode, as it allows vortices to stay coherent.

I am absolutely AMAZED at this thing. I would not have believed that a CFD engine could run that fast in real-time and look so good. I read the paper this thing is based on, and it is [censored] brilliant how they got it to look so good and be stable at arbitrary time step. The scheme is so incredible simple, but looks to incredibly good. It's one of those things where you really want to smack yourself in the head and say, "Why the [censored] didn't I think of that?"

[chezlaw]

wow, this is awesome and so -ev.

chez

[Borodog]

And the music is [censored] intense! Never gets old!

[hmkpoker]

This game pwns so hard.

[FortunaMaximus]

I'll be damned. Very cool.

[Kimbell175113]

Brilliant.

[wazz]

That's so goddamned cool. I'm spamming everywhere with this thing.

[vhawk01]

Any way I can play this without an install? I'm at school and am not allowed to install anything.

[Metric]

Since you read the paper, what's "the trick" that they use to get it to run so well on so little computational power?

[r3vbr]

level 28 on 3rd try
the trick is to focus on the plasma and not on the ball itself

[baumer]

This won't run on my computer. I hate missing out on stupid stuff like this.

[amirite]

This is the first time I've seen this game brought up in a non-drug forum. Other than the huge difficulty variance issues it's an amazing game that can't get enough attention.

[Borodog]

[ QUOTE ]
Since you read the paper, what's "the trick" that they use to get it to run so well on so little computational power?

[/ QUOTE ]

The trick is that they've constructed an extremely simple finite difference scheme that is perfectly stable. To do this, they sacrifice realism for visual verisimilitude.

Having said that though, it's not as though the fluid solver is terrible; it isn't. In the paper they show it the scheme modelling clouds, flames, mushshroom clouds, and show it modelling Rayleigh-Taylor and Kelvin-Helmholtz instabilities.

One "problem" (and it's not really a problem, given the application) is that their scheme is so simple, so low order, that it is pretty inherently numerically dissipative. The equations of fluid dynamics allow for fluid viscosity (more than one kind, in fact), but this code has a fairly high "computational viscosity", which robs the flow of energy. One implication of this is that the code cannot handle true shockwaves; they get "smeared out" by the numerical dissipation because the solver cannot resolve them. This code is like a kid's toy next to the codes I used, but it looks so damn good and runs so damn fast that it blows my mind.

This is a still frame from a 2d test run of one of my codes that I modified to simulate the flow around solid objects (normally there is no need in an astrophysical hydro code to simulate flow around rigid objects, since there aren't any).

http://i27.photobucket.com/albums/c153/Borodog/Wedg2.jpg

[gumpzilla]

As a game, it kinda sucks, mostly for the same reasons that it's a very impressive accomplishment: trying to wrap your head around fluid dynamical behavior isn't likely to get you very far. My playing of the Pong game consisted mostly of just holding the left button down all the time and wiggling back and forth. Meh.

The sandbox mode is pretty slick, though, and it's a very impressive looking piece of software. So thanks.