POV-Ray : Newsgroups : povray.advanced-users : Converting Halos to Media Server Time
26 Nov 2024 06:22:30 EST (-0500)
  Converting Halos to Media (Message 1 to 6 of 6)  
From: philhall
Subject: Converting Halos to Media
Date: 20 Dec 2000 13:17:22
Message: <3A40F892.A8F39EAF@io.com>
Hey all. After a long absence from POV-ray, I recently downloaded the
new version and discovered the new media statement. In the old version,
I enjoyed using halos to create all sorts of effects, but when I try to
change these halos over to using the new media object, it doesn't look
anything like what it used to. Can someone give me some advice? I've
pasted one of my halo codes below.

-----

		halo{
			emitting
			spherical_mapping
			linear
			turbulence 1.5
			color_map{
				[0 color rgbt <1, 0, 0,  1.0>]
				[0.6 color rgbt <1,1,0,-1>]
				[1 color rgbt <1, 1, 0, -1>]
				}
			 samples 100
			 rotate<0,90,0>
			 scale <0.6,0.5,0.6>
			 }


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From: Chris Huff
Subject: Re: Converting Halos to Media
Date: 20 Dec 2000 14:28:42
Message: <chrishuff-A4B9F8.14294920122000@news.povray.org>
In article <3A40F892.A8F39EAF@io.com>, philhall <phi### [at] iocom> 
wrote:

> Hey all. After a long absence from POV-ray, I recently downloaded the
> new version and discovered the new media statement. In the old version,
> I enjoyed using halos to create all sorts of effects, but when I try to
> change these halos over to using the new media object, it doesn't look
> anything like what it used to. Can someone give me some advice? I've
> pasted one of my halo codes below.

There is no way to directly translate from one to the other, you will 
have to adjust things like density and samples until you get the desired 
effect, but media is a more consistent and flexible model, especially 
when you use the sampling method patches in MegaPOV(a patched unofficial 
version, http://nathan.kopp.com/patched.htm). I never used halo, but a 
rough translation of your code would be:

media {
    emission color White
    samples 100, 100
    //you will probably want to change the samples setting to
    //something more like: samples 75, 125
    //of course, the numbers depend on your scene...if you use
    //MegaPOV and method 2 or 3, you can get away with much smaller
    //numbers.
    density {spherical turbulence 1.5
            //use the "spherical" pattern to control the density
        color_map {
            //I don't know what you meant with the "t" channel, 
            //you will need to adjust the brightness of these colors
            //to get the right results.
            [0.0 color rgb < 1, 0, 0>]
            [0.6 color rgb < 1, 1, 0>]
            [1.0 color rgb < 1, 1, 0>]
        }
    }
    rotate < 0, 90, 0>
    scale < 0.6, 0.5, 0.6>
}

You can generally ignore ratio, variance, and confidence, the defaults 
are usually sufficient. Don't bother messing with transmit or filter, 
the brightness of the color defines the density, black is completely 
transparent. Try experimenting with emission media at first, it is the 
fastest rendering.

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

<><


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From: philhall
Subject: Re: Converting Halos to Media
Date: 20 Dec 2000 15:03:30
Message: <3A41116E.42279D13@io.com>
Chris Huff wrote:
> media {
>     emission color White
>     samples 100, 100
>     //you will probably want to change the samples setting to
>     //something more like: samples 75, 125
>     //of course, the numbers depend on your scene...if you use
>     //MegaPOV and method 2 or 3, you can get away with much smaller
>     //numbers.
>     density {spherical turbulence 1.5
>             //use the "spherical" pattern to control the density
>         color_map {
>             //I don't know what you meant with the "t" channel,
>             //you will need to adjust the brightness of these colors
>             //to get the right results.
>             [0.0 color rgb < 1, 0, 0>]
>             [0.6 color rgb < 1, 1, 0>]
>             [1.0 color rgb < 1, 1, 0>]
>         }
>     }
>     rotate < 0, 90, 0>
>     scale < 0.6, 0.5, 0.6>
> }
> 
> You can generally ignore ratio, variance, and confidence, the defaults
> are usually sufficient. Don't bother messing with transmit or filter,
> the brightness of the color defines the density, black is completely
> transparent. Try experimenting with emission media at first, it is the
> fastest rendering.

Thanks for your help. I'm getting slightly better results with your
advice but it still looks like a big splotch of color. I'm basically
trying to make a nebula type effect inside of a glass sphere. If density
is controlled by the brightness of the color, how can I get a nebulous
effect with vivid colors? Also, I don't seem to be able to get any
turbulence. Its more sort of rings of color that fade into each other.
Do you have any more advice or could you point me to some place that has
good examples and descriptions of getting this media thing to look good? 

-Phil


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From: C J 
Subject: Re: Converting Halos to Media
Date: 20 Dec 2000 15:08:52
Message: <3a4111d4$1@news.povray.org>
Phil,
I have 3 media tutorials in the PRSG that may help you. Look in POV Advanced
under the tutorials section.

www.croswinds.net/~povstudy

Hope it helps,
C.J. - POV User


"philhall" <phi### [at] iocom> wrote in message
news:3A41116E.42279D13@io.com...
> Chris Huff wrote:
> > media {
> >     emission color White
> >     samples 100, 100
> >     //you will probably want to change the samples setting to
> >     //something more like: samples 75, 125
> >     //of course, the numbers depend on your scene...if you use
> >     //MegaPOV and method 2 or 3, you can get away with much smaller
> >     //numbers.
> >     density {spherical turbulence 1.5
> >             //use the "spherical" pattern to control the density
> >         color_map {
> >             //I don't know what you meant with the "t" channel,
> >             //you will need to adjust the brightness of these colors
> >             //to get the right results.
> >             [0.0 color rgb < 1, 0, 0>]
> >             [0.6 color rgb < 1, 1, 0>]
> >             [1.0 color rgb < 1, 1, 0>]
> >         }
> >     }
> >     rotate < 0, 90, 0>
> >     scale < 0.6, 0.5, 0.6>
> > }
> >
> > You can generally ignore ratio, variance, and confidence, the defaults
> > are usually sufficient. Don't bother messing with transmit or filter,
> > the brightness of the color defines the density, black is completely
> > transparent. Try experimenting with emission media at first, it is the
> > fastest rendering.
>
> Thanks for your help. I'm getting slightly better results with your
> advice but it still looks like a big splotch of color. I'm basically
> trying to make a nebula type effect inside of a glass sphere. If density
> is controlled by the brightness of the color, how can I get a nebulous
> effect with vivid colors? Also, I don't seem to be able to get any
> turbulence. Its more sort of rings of color that fade into each other.
> Do you have any more advice or could you point me to some place that has
> good examples and descriptions of getting this media thing to look good?
>
> -Phil


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From: philhall
Subject: Thanks!
Date: 20 Dec 2000 19:57:26
Message: <3A41565C.9CFFACF0@io.com>
Thanks for the help guys! I've got the media working how I want to. I
appreciate the quick, helpful responses.


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From: C J 
Subject: Re: oops
Date: 21 Dec 2000 13:39:24
Message: <3a424e5c$1@news.povray.org>
this is the correct address....
www.crosswinds.net/~povstudy
Regards,
C.J.


"C.J." <hou### [at] yahoocom> wrote in message
news:3a4111d4$1@news.povray.org...
> Phil,
> I have 3 media tutorials in the PRSG that may help you. Look in POV
Advanced
> under the tutorials section.
>
> www.croswinds.net/~povstudy
>
> Hope it helps,
> C.J. - POV User
>
>
> "philhall" <phi### [at] iocom> wrote in message
> news:3A41116E.42279D13@io.com...
> > Chris Huff wrote:
> > > media {
> > >     emission color White
> > >     samples 100, 100
> > >     //you will probably want to change the samples setting to
> > >     //something more like: samples 75, 125
> > >     //of course, the numbers depend on your scene...if you use
> > >     //MegaPOV and method 2 or 3, you can get away with much smaller
> > >     //numbers.
> > >     density {spherical turbulence 1.5
> > >             //use the "spherical" pattern to control the density
> > >         color_map {
> > >             //I don't know what you meant with the "t" channel,
> > >             //you will need to adjust the brightness of these colors
> > >             //to get the right results.
> > >             [0.0 color rgb < 1, 0, 0>]
> > >             [0.6 color rgb < 1, 1, 0>]
> > >             [1.0 color rgb < 1, 1, 0>]
> > >         }
> > >     }
> > >     rotate < 0, 90, 0>
> > >     scale < 0.6, 0.5, 0.6>
> > > }
> > >
> > > You can generally ignore ratio, variance, and confidence, the defaults
> > > are usually sufficient. Don't bother messing with transmit or filter,
> > > the brightness of the color defines the density, black is completely
> > > transparent. Try experimenting with emission media at first, it is the
> > > fastest rendering.
> >
> > Thanks for your help. I'm getting slightly better results with your
> > advice but it still looks like a big splotch of color. I'm basically
> > trying to make a nebula type effect inside of a glass sphere. If density
> > is controlled by the brightness of the color, how can I get a nebulous
> > effect with vivid colors? Also, I don't seem to be able to get any
> > turbulence. Its more sort of rings of color that fade into each other.
> > Do you have any more advice or could you point me to some place that has
> > good examples and descriptions of getting this media thing to look good?
> >
> > -Phil
>
>


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