This topic contains 22 replies, has 0 voices, and was last updated by  Anonymous 13 years, 4 months ago.

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  • #2524

    mstock
    Participant

    Hey, I’m new to Scorched3D, but I player the original scorch on the 386s way back when. I love the game, and I love what you folks have done here!

    I mention the mushroom clouds because I think I may have come upon a fast method to do fluid dynamics in 3D…a method that could be run at super-low resolution, but still create really nice-looking mushroom clouds in real-time—custom-simulated every time.

    Here’s a link to a small (http://mark.technolope.org/vic2d/mov46s.mpg) 2D animation that I just made. The MPG file is 66kB and has 50 frames. It is an animation of a 2D thermal, the source of the mushroom cloud. Keep in mind that 3D thermals will rise higher and spread more narrowly than 2D thermals, and will look more realistic.

    I suppose the fluid backend would simply serve to move the smoke-like particles until they die out. The same number of particles could be used, and the effect would look much more realistic.

    I am hoping that the code can be upgraded to 3D relatively easily, and I will try to include support for uneven ground conditions. A mushroom cloud next to a cliff will turn toward the cliff and climb up it. It might also be nice to animate the shock wave emanating from the explosion, though I don’t know if that’d be possible.

    Please tell me if this is something you’d be interested in seeing, and that I should pursue coding.

    #11277

    Cambo
    Participant

    I’ve been working on a 3d model for the mushroom cloud, but I’ve been so busy lately (plus it doesn’t look good when it’s on the scale of the current one). Obviously you have some experience with fluid dynamics (peeked at your thesis…arg.. way over my head). Your welcome to try (the movie looks good).

    When you’re done you can email it to gavin and he’ll look at merging it to the source code…. Just remember he’s on vacation for the week.

    Cam

    #11278

    mstock
    Participant

    Cool. I’ll give the 3D version a try in the next few weeks. What information are you going to want on input? The easiest thing to do, for starters, would be to accept an x,y,z location and scale to an initializer routine, which would return initial particle locations. Then, calls to another time-stepping routine would take the particle positions and move them.

    Later on (and if it works), the routine could accept some information about the local terrain during initialization.

    Thanks for giving me the opportunity to help!

    #11279

    imported_gcamp
    Participant

    The clip looks great.

    The easiest thing to do, for starters, would be to accept an x,y,z location and scale to an initializer routine, which would return initial particle locations. Then, calls to another time-stepping routine would take the particle positions and move them.

    Sounds ideal. This is pretty much how it is done at the moment.

    Thanks for giving me the opportunity to help!

    Not at all. Hope you get enough time for it.

    #11280

    Knochi
    Participant

    That’s what i’m waiting for !
    Realistic Nuke Explosions and Mushrooms would be great… pls tell us any progress 🙂 (uh bad english i know)

    Perhabs you want to take a look at a few real explosions…

    Pics and a lot of Background Material at
    http://nuclearweaponarchive.org/index.html

    Take a look at these Quicktime Movies (especially the AtomicCannon):
    http://www.vce.com/AtomicGallery/AtomicGallery.html

    I know… a little bit sick… but… who cares 😈

    #11281

    mstock
    Participant

    @knochi wrote:

    That’s what i’m waiting for !
    Realistic Nuke Explosions and Mushrooms would be great… pls tell us any progress 🙂 (uh bad english i know)

    Perhabs you want to take a look at a few real explosions…

    Pics and a lot of Background Material at

    Take a look at these Quicktime Movies (especially the AtomicCannon):

    I have seen the first link before, and am also pretty critical of other CG explosions, so I think that if this works, it’ll look pretty good. The overall dynamics are the most important to me, not the texturing or other details.

    I would love to see the movies at the second link, but I can’t find a way to just download the quicktimes. They don’t play in the popup window for me. It bugs me when web designers think that downloading and saving files is too difficult for surfers to handle.

    I’ll keep you informed of any progress that I make.

    #11282

    Knochi
    Participant

    Ok i have made a mirror of the AtomicCannon Movie and the WideScreen Explosion.

    Gavin… perhabs you could use the Sounds of the AtomicCannon in further Versions ?!? They sound awesome !

    Atomic Cannon

    WideScreen Explosion

    btw… nice car 8)

    And this “little” Simulations…. kewl !

    #11283

    mstock
    Participant

    @knochi wrote:

    Ok i have made a mirror of the AtomicCannon Movie and the WideScreen Explosion.

    btw… nice car 8)

    Thanks, You wouldn’t know where I could get a working 472 ci engine from, would you?

    Cool. Thanks for putting those movies up there. It’s obvious how good dynamics can really make a difference. The sounds are good, too!

    #11284

    Knochi
    Participant

    Errr…. ebay ?
    🙄

    #11285

    mstock
    Participant

    I spent most of my Saturday writing the 3D version. I’m still missing the dissipation term (no biggie) and I need to find the source of some dynamic weirdness. I hope to be able to share an early animation soon. It runs more slowly in 3D that I had expected. In order to allow it to run realtime, it may have to work at extremely low resolutions. We’ll see.

    At the very least, I could run it at higher resolutions, and just set up predefined particle paths. The advantage is fast animation and better detail, the disadvantage is that it’s canned, and won’t react to close mountains, etc. I can predefine a few cases with different cross-wind speeds, and different weapon sizes.

    #11286

    ruinzV2.0
    Participant

    well the radius of the cloud shouldnt be much bigger then the explosion itself. since the explosion will remove the mountain in its range i dont see why having it not react would be much of a big deal. just my thought, i dont know how your making it or anything though so you can tell me to shut up=P

    #11287

    mstock
    Participant

    You’re right. Just having some realistic dynamics of the cloud itself is an improvement over most other games, anyways. The extra interaction with the terrain is just gravy. Someday we’ll want gravy, though.

    I think you’d be impressed with how realistic this can look with a moderate amount of effort. Of course, since I haven’t delivered anything, anyways, my word is just about worthless. =0)

    #11288

    Knochi
    Participant

    How you are doing with the 3D Version ? I’m realy interested in your first previews.

    What about adding a blastline or shockwave ? (Look at vce.com)

    #11289

    mstock
    Participant

    Well, I figured out what I was doing wrong, and I fixed it. I can now present some representative 3D motions. The simulation below is of a warm hemisphere of fluid rising in a closed, still box. It was computed at 33x33x33 resolution on my P4-1.6 in a little over 1 sec per frame.



    Here is an MPG (129kb)

    There isn’t much detail at this resolution, but the overall dynamics are right. Particle paths will be subject to Brownian motion, and that will provide more of the impression of detail. Because these are just the field values, there is little perceptible detail.

    It now appears certain that the code will not be able to run real-time within the program. I will have to precompute particle locations and speeds and recall them as the calling program wishes. Maybe in the future we’ll be able to compute custom motions, but not yet.

    I also did some math for a new dissipation term that will allow the simulation to represent large-scale flow. Right now, I have a pure viscous diffusion term, but I want to add a sub-filter-scale dissipation term to the code.

    I got a great book for my birthday: 100 Suns, a collection of rescanned photographs from the US nuclear tests. I have been studying it for the last few weeks, and have noticed a lot of interesting physical effects.

    The blastline is something that I intend to include. I haven’t yet written the formula for the speed of the shockwave. Once I figure that out, I can include a condensation wave and cloud and the proper amount of ground dust kickup. Once we can get the particles created correctly, the motions will look more accurate because the mushroom cloud will be shaped more like what appears in photographs.

    #11290

    Anonymous
    Participant

    just a quick comment.. how about wind, surely that effects a mushroom cloud?

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