animation of smoke/vortices.

[MrIdiot]

ok i really need some advice! i have been set a project involving animating effects of projectiles and entities of varying size and speed moving through a scene and creating a visible vortex behind them.

examples i was given included projectiles moving through smoke, a car travelling down a road covered in leaves and sucking the leaves up behind it as it goes over them, etc.

i have been advised that i should not use fluid dynamics techniques to do any of this because i dont have the maths for it, but i dont really see how else its possible to achieve these effects.

i've had a good look through all the research papers i can find but i cant find anything thats given me a clue of how it can be done without fluid dynamics. it also seems to be an extremely difficult problem, Fedikew and Stam amongst others have done excellent animations of smoke using various techniques from fluid dynamics but i'm not sure how (or if its even possible) they could be extended to include projectiles firing through the scene. i also couldnt find anything about leaves or other things that could be used for similar effects.

if anyone has any ideas or could point me in the direction of any relevant information i'd be really greatful, at the moment i'm feeling like i cant do this!

[bignobody]

I don't have any links, but google around for particle effect tutorials. You can achieve a lot of cool effects (like the ones you describe) with some pretty simple vector math. No need to go all crazy with the fluid dynamics ;)

[roel]

If you want something close to realism (for the average viewer) and something that isn't 100% academic and mathematical correct, you can read this: http://www.double.co.nz/dust/GDC03.pdf
You don't even have to fully understand the navier-stokes equation and such, the pdf even supplies C code (2D however, but easy to extend to 3D).

On the other hand, as far as I know do most games hack the things you described, like: "is the car above ground covered with leaves -> emit random leaves at the back of the car proportional to its speed". Nobody will notice it and it looks cool :)

[Scuppy]

Nice one roel

[0cool40]

you can use 3dsmax space worps to make the smoke partucles fall with gravity space worps and the vortex space worps to pull in the partucles i use this a lot and others
for dust ,smoke debree effects.

[0cool40]

you can use real leaves photos use photo shop to select them cut them out make diff still photos of them falling then use macromedia director to run the still bitmaps in a time line or make your anumation in 3dsmax or your fav software then save the anumation as bitmaps stills,take that to director lay them out in the time line and add more effects with adobe after effects or discreets combustion it has cool explotions ,
fire effects all ready made.just render them composed with your anumation. also
3dsmax has a cool thing called trejecterys that shows the path that the anumated object takes thay are called keys dotted lines.you can add more keys to drag it around and make it act the way you want hope this helps

[0cool40]

if you use 3dsmax try the plug in that was used to make the tornado and smoke in the movie twister & the day after it is called after burn go to http://www.afterworks.com/
AfterBurn is a production-proven volumetric effects plugin that has been used in cinematic productions such as Matrix Reloaded, Armageddon, Dracula 2000, HBO trailer, Mechwarrior3 cine trailer, various IMAX movies and games such as Warcraft3, Starcraft, Sin and many others.

This all-in-one solution enables rendering of ultra realistic effects ranging from clouds, pyroclastic smoke, dust, superb explosions effects, liquid metals, water and various procedurally defined "hard" objects.