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I used media to render my density file, the code piece is like follows:
#declare container=object{
box {<0,0,0>, <1,1,1>
pigment {rgbt <1,1,1,1>}
interior {
media {
emission 1.
intervals 1
samples 5
method 3
density {
density_file df3 DENSFILE interpolate 1
color_map{
[0 rgb<0.12*2, 0.14*2, 0.225*2>]
[iso_value rgb <0.6, 0.6, 0.0>]
[1. rgb <1.3, 1.3, 0.0>]
}
}
}
}
hollow
}
}
In the code, DENSFILE represents my density file. and i get the result as
shown in the right image.
But i want to get a kind of result as shown in the left image(Feldmann et
al. did it in their siggraph paper), where the pattern of their smoke looks
clearer with the background, and the edge of smoke appears sharpish and the
transparency looks beautiful...
I want to achieve the similar effect, then what's you guys' idea??
thanks for your attention on this message!
Post a reply to this message
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From: Thomas de Groot
Subject: Re: I want to use media to render like this~~
Date: 25 Aug 2006 03:31:13
Message: <44eea741@news.povray.org>
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To me, it looks like the container is textured, perhaps with media inside, I
cannot tell. But the sharp smoke edges suggest that.
Just my 2 Euro-cent...
Thomas
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web.44ee75ddd9d40880598059850@news.povray.org...
> I used media to render my density file, the code piece is like follows:
>
> In the code, DENSFILE represents my density file. and i get the result as
> shown in the right image.
>
> But i want to get a kind of result as shown in the left image(Feldmann et
> al. did it in their siggraph paper), where the pattern of their smoke
looks
> clearer with the background, and the edge of smoke appears sharpish and
the
> transparency looks beautiful...
>
> I want to achieve the similar effect, then what's you guys' idea??
>
> thanks for your attention on this message!
>
I may be wrong (I've not tested) but why don't you try putting max density
at iso_value entry with density 0 just slightly above and below iso_value?
density {
density_file df3 DENSFILE interpolate 1
color_map{
[iso_value -.01 rgb 0]
[iso_value rgb 1] //or any value
[iso_value +.01 rgb 0]
}
}
may need some teaking
Marc
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remember that smoke is (IIRC) mostly particulate matter in suspension.
- so when they form a vortex ring like that, they are more dense near the
outside of the object (I think in that particular case it has something to
do with rotational intertia). Thus, when you are looking at the edge, the
light
must travel through/bounce off of more particles than when you look through
the center. A spherical density gradient in your media would have a similar
look - but this effect only occurs in some forms of smoke. A smoke ring is
a special case. If you really want good smoke simulation, then, well, a
simulation is what you are going to want - or at least a few pictures of
real smoke to attempt to duplicate by hand. Fluid dynamics is, um, hard ;)
--
-s
5TF!
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"lien0n" <nomail@nomail> wrote in message
news:web.44ee75ddd9d40880598059850@news.povray.org...
>I used media to render my density file, the code piece is like follows:
>
> #declare container=object{
> box {<0,0,0>, <1,1,1>
> pigment {rgbt <1,1,1,1>}
> interior {
> media {
> emission 1.
> intervals 1
> samples 5
> method 3
>
> density {
> density_file df3 DENSFILE interpolate 1
> color_map{
> [0 rgb<0.12*2, 0.14*2, 0.225*2>]
> [iso_value rgb <0.6, 0.6, 0.0>]
> [1. rgb <1.3, 1.3, 0.0>]
> }
> }
> }
> }
> hollow
> }
> }
>
> In the code, DENSFILE represents my density file. and i get the result as
> shown in the right image.
>
> But i want to get a kind of result as shown in the left image(Feldmann et
> al. did it in their siggraph paper), where the pattern of their smoke
> looks
> clearer with the background, and the edge of smoke appears sharpish and
> the
> transparency looks beautiful...
>
> I want to achieve the similar effect, then what's you guys' idea??
>
> thanks for your attention on this message!
>
Put all your density on a surface (outer edges of cloud), perhaps a
transparent texture map will work, or build a volume approximating to a thin
surface shell and fill that with suitable media.
DLM
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hi, everyone, sorry that i can't log in these days.
In fact, i create the DENSFILE with a physically-based fluid simulation
method (i wrote it! :)), and i want to use "media" to render my simulation
result. The DENSFILE represent the density field of my result, which is
actually a scalar 3D array, or a 3D texture. Therefore, i think the "media"
object in povray is the tool i want...
Feldman (the author of the left image) use pixie to render the left image.
They use plenty of particles to represent their smoke.
However, i want to know that if it is possible for me to use the media
object to achieve similar effects.
Post a reply to this message
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"dlm" <me### [at] address invalid> wrote:
>
> Put all your density on a surface (outer edges of cloud), perhaps a
> transparent texture map will work, or build a volume approximating to a thin
> surface shell and fill that with suitable media.
>
> DLM
thanks, DLM.
but what is the transparent texture map, and how to use it?
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Hi lien0n,
Transparency (really opacity) is controlled by using the alpha channel in
the image_map graphic which wraps a 2D image onto a 3D surface. See
http://www.povray.org/documentation/view/3.6.1/337/
DLM
"lien0n" <nomail@nomail> wrote in message
news:web.44f25299a61f9468598059850@news.povray.org...
> "dlm" <me### [at] address invalid> wrote:
>>
>> Put all your density on a surface (outer edges of cloud), perhaps a
>> transparent texture map will work, or build a volume approximating to a
>> thin
>> surface shell and fill that with suitable media.
>>
>> DLM
>
> thanks, DLM.
>
> but what is the transparent texture map, and how to use it?
>
Post a reply to this message
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whats happen if you add fade_power and fade_distance in your interior
statement and play with ?
news:web.44ee75ddd9d40880598059850@news.povray.org...
> I used media to render my density file, the code piece is like follows:
>
> #declare container=object{
> box {<0,0,0>, <1,1,1>
> pigment {rgbt <1,1,1,1>}
> interior {
> media {
> emission 1.
> intervals 1
> samples 5
> method 3
>
> density {
> density_file df3 DENSFILE interpolate 1
> color_map{
> [0 rgb<0.12*2, 0.14*2, 0.225*2>]
> [iso_value rgb <0.6, 0.6, 0.0>]
> [1. rgb <1.3, 1.3, 0.0>]
> }
> }
> }
> }
> hollow
> }
> }
>
> In the code, DENSFILE represents my density file. and i get the result as
> shown in the right image.
>
> But i want to get a kind of result as shown in the left image(Feldmann et
> al. did it in their siggraph paper), where the pattern of their smoke
looks
> clearer with the background, and the edge of smoke appears sharpish and
the
> transparency looks beautiful...
>
> I want to achieve the similar effect, then what's you guys' idea??
>
> thanks for your attention on this message!
>
----------------------------------------------------------------------------
----
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"NEWS" <pen### [at] caramail fr> wrote:
> whats happen if you add fade_power and fade_distance in your interior
> statement and play with ?
>
I tried and the results were not so good to play with fade_power and
fade_distance, but i found that authors of the left image just render their
result with millions of particles, so the left image looks so cool~~~~~,
And now i draw the conclusion that it's impossible to achieve the same
result by using the media object, anybody disagree with me??
> news:web.44ee75ddd9d40880598059850@news.povray.org...
> > I used media to render my density file, the code piece is like follows:
> >
> > #declare container=object{
> > box {<0,0,0>, <1,1,1>
> > pigment {rgbt <1,1,1,1>}
> > interior {
> > media {
> > emission 1.
> > intervals 1
> > samples 5
> > method 3
> >
> > density {
> > density_file df3 DENSFILE interpolate 1
> > color_map{
> > [0 rgb<0.12*2, 0.14*2, 0.225*2>]
> > [iso_value rgb <0.6, 0.6, 0.0>]
> > [1. rgb <1.3, 1.3, 0.0>]
> > }
> > }
> > }
> > }
> > hollow
> > }
> > }
> >
> > In the code, DENSFILE represents my density file. and i get the result as
> > shown in the right image.
> >
> > But i want to get a kind of result as shown in the left image(Feldmann et
> > al. did it in their siggraph paper), where the pattern of their smoke
> looks
> > clearer with the background, and the edge of smoke appears sharpish and
> the
> > transparency looks beautiful...
> >
> > I want to achieve the similar effect, then what's you guys' idea??
> >
> > thanks for your attention on this message!
> >
>
>
> ----------------------------------------------------------------------------
> ----
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