Well, now that I know properly how trace() works, why haven't I
seen a scene with particles bound around in a little room, stuffed with
some sphere, cylinders and boxes?

You know, I'd really like to see some physical action there, though I
perhaps
should consider that your (all of you particle-system programmers)
algorithm
for particles lying on a surface have some drawbacks (I had some tricky
stuff
to do until my particles stayed on the ground without problems)...

You see, the drawback of my system, is that it can only calculate
physical rebounce
with a box, which has to be declared beforeend, though I think your
systems
could work with about any set-up of scene, or am I wrong?

I'm not talking about animated objects, just motionless objects, off
which the
particles are repelled.

I hope it's possible and that someone will create an awesome animation
from
this idea...

See you all,

Tim

Post a reply to this message

"Tim Nikias" wrote:
> Well, now that I know properly how trace() works, why
> haven't I seen a scene with particles bound around in
> a little room, stuffed with some sphere, cylinders and
> boxes?

Because all people don't necessarily have the same idea as you of what the
"ultimate show-off animation" is. I personally find collisions with spheres,
cylinders and boxes a bit boring because they're just simple geometric
shapes, and they don't occur much in the real world. But I've done a few
animations with collisions with height-fields, which you can see on my
website.

> You know, I'd really like to see some physical action there

We're not mind-readers. We have done lots of animations and if they don't
happen to please your exact tastes, that's not our problem.

If you ask us to try out a specific idea for an animation, maybe one of us
will try it out if you're lucky, but really, we do mainly what *we* think is
fun...

> I hope it's possible and that someone will create an awesome
> animation from this idea...

I think there have been lots of awesome animations already. It's very
difficult to know what your idea of "an awesome animation" is.

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated Nov 5)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

Post a reply to this message

Sorry!

Your reply sounded like I insulted you or something, which wasn't the
point I was trying to make.

The particle-action I've seen so far is really astonishing, your animation
with the particles rolling on the "uneven disc-thingy" looked really cool!

What I was thinking if someone could create something that would
have more than "particles interact with one object". Your animation with
the two gravitational spheres was something I had in mind for that.

My system doesn't have the possibities to react to more than a box
(it may not be rotated!), and that's a drawback I have.

But your systems (not only yours, Rune, but the others as well) looks like
they're capable of doing some pretty stuff. Also, I'd guess, having particles
scatter
through a room filled with objects would be an extensive test for the systems.

If I come up with a more specific idea, I'll tell, okay?

Tim

Post a reply to this message

"Tim Nikias" wrote:
> Sorry!
>
> Your reply sounded like I insulted you or something,
> which wasn't the point I was trying to make.

I wasn't insulted, it just sounded like you was surprised that we had not
*already* made the exact kind of animation you had in mind, and I wanted to
sort that out.

> The particle-action I've seen so far is really
> astonishing, your animation with the particles
> rolling on the "uneven disc-thingy" looked really cool!

Thanks. You do realize that it consisted of several objects (though they
were put in a union)?

> What I was thinking if someone could create something
> that would have more than "particles interact with one
> object".

There have been lots of animations where particles interact with more than
one object. Look through this group and you'll find them.

> Also, I'd guess, having particles scatter through a room
> filled with objects would be an extensive test for the systems.

Not really.

> If I come up with a more specific idea, I'll tell, okay?

Sure. If I find it interesting, maybe I'll even try it out!

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated Nov 5)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

Post a reply to this message

>
> Thanks. You do realize that it consisted of several objects (though they
> were put in a union)?
>

I did realize that, and also... (goes on below)

>
> There have been lots of animations where particles interact with more than
> one object. Look through this group and you'll find them.
>

...I know that there are often several planes or boxes used to limit the
particles to a certain boundary.

>
> > Also, I'd guess, having particles scatter through a room
> > filled with objects would be an extensive test for the systems.
>
> Not really.
>

Why not? If particles run into tight spaces, don't the faults in coding appear?

I've found a calculation error when rendering one animation. A particle hit
a corner, which would imply rebouncing off two positions at once. The system,
of course, calculated only one, but skipped the second, as the algorithm then
sorted it out as being a rebounce that would take place if the particle
would actually move backwards in time.
Thus, a particle bounced out of the boundary box and moved on out there!

One idea I just had for an animation:
Consider a three-storey house. No columns, no doors, no windows. Just
three empty room atop of each other. In the floor of the third and second
room are holes, different kinds of shapes, but not too big. Now, have
particles fall from the ceiling of the third room, and as some'll drop through,

they gain more speed and bounce upwards again, perhaps with enough force
as to re-enter a room above.
I know, thinking about it, it's pretty simple, but I'd like to see that kind of

animation. It's just something neat to play with, I guess.

You know those games in little plastic boxes, in which you have a maze or
some holes, into which you have to drop some metal balls?
It's just fun to look at, that's all.

Tim

Post a reply to this message

Tim Nikias wrote:

>
> Why not? If particles run into tight spaces, don't the faults in coding appear?
>

I tend to agree with Rune here. In testing my system, I keep the scene simple (to
keep render times down), and only include the nessecaries. If I wanted to test what
happens to my particles in a corner, then the scene might contain a floor, two
walls (for the corner), and a small sample of particles heading for that corner set
up so that I could observe any problems. I'll leave the complex scenery to those
who have patience and artistic talent.

MJL

Post a reply to this message