This is something I've wanted to do all since glows first came out. Don't
know why I haven't come around to doing it before, because it was pretty
straightforward and took me only an evening to do (though it can still be
improved).

What do you think?

Rune
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Attachments:
Download 'fairies.mpg' (98 KB)

Nice effect!
That green one looks really bright. It look s brighter than normal rgb 1. Is
it achieved by just using a glow or are there any secrets involved. If the
later, care to share? ;-)

Marc-Hendrik

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Very cool thing.  Brightness is illusion I'd say.  Does this use the C.C. spray
include, or not?  Or something you came up with maybe?

Bob H.

"Marc-Hendrik Bremer" <Mar### [at] t-onlinede> wrote in message
news:3a869f36@news.povray.org...
> Nice effect!
> That green one looks really bright. It look s brighter than normal rgb 1. Is
> it achieved by just using a glow or are there any secrets involved. If the
> later, care to share? ;-)

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"Marc-Hendrik Bremer" wrote:
> Nice effect!

Thanks!

> That green one looks really bright. It look s brighter than normal rgb 1.
> Is it achieved by just using a glow or are there any secrets involved.

Normally monitors are limited in brightness to rgb 1, but I used the new
MPGlow video codex that expands the range of brightness by bending the
cathode ray to shoot more electrons at the brighter parts of the screen. Or,
if you don't buy that, it's just a visual illusion caused by the glows... ;)

Rune
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"Bob H." wrote:
> Very cool thing.

Thanks!

> Does this use the C.C. spray include, or not?

Not. I'm not sure the spray include supports moving emitter-points.

> Or something you came up with maybe?

Yes. It's a simple POV-script particle system (not related to the particle
patch). It creates particles along a moving emitter-point. These particles
have slightly different start-velocity-vectors, and they're all affected by
gravity.

Rune
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"Pretty straightforward"?! I can't even imagine how to do that... Explain...
please.

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On Sun, 11 Feb 2001 16:05:35 +0100, "Rune" <run### [at] inamecom> wrote:
>
>Normally monitors are limited in brightness to rgb 1, but I used the new
>MPGlow video codex that expands the range of brightness by bending the
>cathode ray to shoot more electrons at the brighter parts of the screen. 
>
I thought that expansion of the dynamic range of a crt was usually done by
sublimating a quark/positron attractor on to the anode and modulating the sweep
frequency with a uv component.  I may be wrong though.
----------------------
dav### [at] hamiltonitecom
http://hamiltonite.com/

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"Tony[B]" wrote:
> "Pretty straightforward"?!

Erm, hehe, pretty straightforward to *me* since I've done POV-script
particle systems before, so there was not much new in this one... :D

I'm also sure other's here who have worked with particle systems would think
that this one is nothing special. It looks nice nonetheless.

> I can't even imagine how to do that... Explain...
> please.

Ok, you asked for it. Let's see, where to start...

The core of the particle systems is two arrays, one containing the current
location of each particle and the other containing the last location.
There's also an array for the life of each particle (it goes downwards, and
when it reaches zero the particle dies) and one for the color (yes, all the
particles have slightly different colors).

The same calculations are done over and over again. In each calculation step
all the particles are moved slightly 1) , some particles die 2) and some new
ones are born 3).

1) Each particle is moved by it's current velocity (current location minus
last location) plus gravity. More forces could be added if necessary. The
life is also decreased by an amount.

2) In each calculation-step some particles die (Life goes below 0). It
seemed like I couldn't use #undef with individual array elements, so I set
the color to <0,0,0> instead and detected empty elements that way instead.

3) In each calculation step new particles are also created (they are created
in empty elements). Their initial "last" location is set equal to the
current position of the emitter-point. Their initial "current" location is
the same as the "last", but with some randomness added. The particle is also
given a color (user-defined color plus some randomness) and it's life is
initialised.

For each frame in the animation a number of calculation steps are done.
After the last step for a given frame, the glows are created according to
the latest calculated locations, and after that, file I/O is used to save
the data in a file to make it available to the next frame in the animation.

So you see, it's pretty straightforward! ;)

Rune
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\ Include files, tutorials, 3D images, raytracing jokes,
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beautiful- details please!


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oh here are the details... thanks!!!
-- 
Yeah, but ask yourself... why are you really
interested?
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