Re: Particle systems

[TI95NEUK@de.ibm.com]

Hi Keith, (and all others),

some interesting thoughts. But here is how I (and most people I know) do it
usually:

- As soon as a particle is emitted, it's independend from the emitter.
- (Simple) Particels are defined by: x,y,z,direction,speed,mass, "looks",
timeToLife, (dieFunc)
- (Simple) "looks" are defined by type (pixel, image), color, size, map,
alphamap, animator

All your FX are/can be particels (clouds, dust, fire, smoke, ...).

There is usually no need for "local" and "global" particels.
Maybe I missed your point, but I didn't understand the real question.

ciao
Anti



"Keith Lucas" <klucas@atlan-tech.com> on 12/07/99 11:08:47 AM

I've got particle systems working, it's all running fine. So now I'm wondering
how to actually use them...

Here's my thought: particle systems are an effect. Other effects include a cloud
of smoke or a dust. An effect knows its posn, velocity, evolution, time to die
off, that sort of thing. So a rocket motor is a low-level effects emitter
throwing off smoke clouds which then drift in the wind and so on. An
unsuccessful rocket impact is another that throws off a bundle of glowy blobs
and then dies. Burning debris from an explosion has both a particle system,
which emits the flames and an effects emitter which throws off the smoke-trail.

Does this sound like the sort of thing people do? I mean basically it's having
two types of particles, one which is relative to the particle system's
"location" and one which is global. Which should make culling them and depth
sorting them easier. Does it sound sane or is there some other approach?


{This is something else that doesn't get mentioned in text-books. They all stop
at the "emit particles and, erm, subject them to gravity" level. Nothing about
what you do to model smoke trails from surface-to-air missiles in a reasonable
way.}