When someone who is hiding around a corner shouts at me, I don't look AT
them, I look at the area of maximal density of soundwaves that have (?)

for this or to accomplish it with current syntaxes?

the density function might look like this....

---------------------+
10 10 9 8 7 6 5 4 3 2|
11 10 9 8 7 6 5 4 3 2|
10 10 9 8 7 6 5 4 3 2|
--------------+ 4 3 2|



This could be useful for explosions that go down a hallway or a few
other eclectic applications that only I might use ;)

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Greg M. Johnson wrote:

>the density function might look like this....
>
>---------------------+
>10 10 9 8 7 6 5 4 3 2|
>11 10 9 8 7 6 5 4 3 2|
>10 10 9 8 7 6 5 4 3 2|
>--------------+ 4 3 2|


>

Makes me think of df3 or the i_dat3d stuff in megapov. Have a look at the 
idat3darray.pov sample file for megapov, maybe it leads you to something.


Ingo

-- 
Photography: http://members.home.nl/ingoogni/
Pov-Ray    : http://members.home.nl/seed7/

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In article <3a1bd3ff@news.povray.org>, "Greg M. Johnson" 
<"gregj;-()"@aol.c;-()om> wrote:

> This could be useful for explosions that go down a hallway or a few
> other eclectic applications that only I might use ;)

I think this would be a good application of a particle system, having 
the particles bounce through the hallway to simulate the path of the 
explosion. With MegaPOV, it would be easy to code one using the trace() 
function, and use that to place components of a blob pattern to get the 
final result.
With MegaPOVPlus, you could try the particle_system object to do the 
simulation, which should be much faster, but isn't complete yet and is 
less flexible than doing things directly in the scene file. Also, MP+ is 
based on an older MegaPOV and I don't have the updated version done yet, 
and it won't be ready for a while.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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On Wed, 22 Nov 2000 13:38:41 -0500, Chris Huff <chr### [at] maccom>
wrote:

>I think this would be a good application of a particle system, having 
>the particles bounce through the hallway to simulate the path of the 
>explosion. 

Does your particle system account for mass? If so, does it compute the
De Broigle wavelength of a particle? Does it then use its duality to
compute wave effects?

:)))

Sorry, couldn't resist... but really, it's wave behaviour Greg needs
to model.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] usanet
TAG      e-mail : pet### [at] tagpovrayorg

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"Peter Popov" <pet### [at] usanet> wrote in message
news:mhtr1tcav803aeg1aufat5cmlp2hrrvo4t@4ax.com...
>
> Does your particle system account for mass? If so, does it compute the
> De Broigle wavelength of a particle? Does it then use its duality to
> compute wave effects?
>

Mummy, the petey-poppy man is making my ears bleed....

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In article <mhtr1tcav803aeg1aufat5cmlp2hrrvo4t@4ax.com>, Peter Popov 
<pet### [at] usanet> wrote:

> Does your particle system account for mass?

Yes.


> If so, does it compute the De Broigle wavelength of a particle? Does 
> it then use its duality to compute wave effects?

Um, no...but you can probably do something like that yourself, using the 
age of the particle. I don't know what the "De Broigle wavelength" is, 
so I can't tell for sure...


> Sorry, couldn't resist... but really, it's wave behaviour Greg needs
> to model.

I don't think that is necessary. He said he wanted to use it for things 
like explosions going through hallways, a particle system should be fine 
for that. If he wanted to simulate acoustics, it would be 
different...but that type of explosion is more like a fluid(gas or 
liquid) flowing through a pipe than wave behavior.

It might be possible to do something that goes the other way, sort of a 
cross between radiosity and the proximity pattern. You would specify a 
target object and a recursion level, and it would send out samples to 
determine the visibility of the object from any point, even the effect 
around corners. However, this would be incredibly slow...though a sort 
of cache could be used for reusing data, like radiosity has, I don't 
know how to implement that. And the particle system approach could 
probably come closer to simulating wave behavior.

Hmm, maybe some sort of 3D grid, similar to a voxel image, could be set 
up around the immediate area containing all the "free" space, this could 
then be used in waveform simulations...it could be faster, because no 
recursive tracing would need to be done, but would eat memory like crazy 
in large spaces with high resolution. An octree-like structure could be 
optimized for large areas, but areas that are mostly "free" would 
probably use memory best when a simple array is used.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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in povray.general, Chris Huff says...

> > If so, does it compute the De Broigle wavelength of a particle? Does 
> > it then use its duality to compute wave effects?
> 
> Um, no...but you can probably do something like that yourself, using the 
> age of the particle. I don't know what the "De Broigle wavelength" is, 
> so I can't tell for sure...
De Broglie [correct spelling] (a French prince, Nobel prize physics 1929) 
proved that electrons have an inherent wavelength, depending on their 
energy. This is what PP was referring to. It was the first step that was 
leading to the development of quantum mechanics. A clever prince he was! 
-- 
Regards,  Sander

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In article <MPG.1488a233174790f89896b2@news.povray.org>, Sander 
<san### [at] stolscom> wrote:

> De Broglie [correct spelling] (a French prince, Nobel prize physics 1929) 
> proved that electrons have an inherent wavelength, depending on their 
> energy.

Well, I don't think we need to be simulating stimulated emission of 
radiation by electrons changing energy levels, just to do an 
explosion... :-)
I'm not sure what this has to do with acoustic simulations either...

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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Chris Huff wrote:

> I think this would be a good application of a particle system, having
> the particles bounce through the hallway to simulate the path of the
> explosion.


positions after time t, *but then* use blob pattern.

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In article <3a2146ba$1@news.povray.org>, "Greg M. Johnson" 
<"gregj;-()"@aol.c;-()om> wrote:

> Your suggestion is half ingenious.? Set up bouncing particles, record the
> positions after time t, *but then* use blob pattern.

I thought that was exactly what I was suggesting...I must have 
misunderstood, could you clarify what you meant?
Which was the "ingenious" part? The blob pattern, the trace() function, 
or using the particle_system to do the work for you instead of writing 
your own particle system?

"...code one using the trace() function"
Many people have talked about using trace() for collision detection for 
particles, and it has been done several times...that certainly isn't a 
new idea.

"...place components of a blob pattern to get the final result."
I have suggested the blob pattern for this type of thing from it's 
creation. In fact, it is designed as a media density pattern with fire 
and smoke in mind...

"...you could try the particle_system object to do the simulation..."
This last one can't be it, since the ability to use the particle_system 
only to do the simulation is one of it's main features. Again, nothing 
new...

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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