Is there a tutorial somewhere on how to create realistic looking mountains
in POV without using image files as heightfields (for example using the
isosurfaces in MegaPOV)? Or could someone reply to this message and explain
the basics?


--ll

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In article <38c38e9c@news.povray.org>, "Lars Luthman" <no### [at] spamse> 
wrote:

> Is there a tutorial somewhere on how to create realistic looking 
> mountains in POV without using image files as heightfields (for 
> example using the isosurfaces in MegaPOV)? Or could someone reply to 
> this message and explain the basics?

Well, you can use a height field without an image, using a pattern 
instead. To do that you use the "pattern" keyword. Here is the syntax 
and a sample copied from the MegaPOV documentation:

pattern Width, Height { [ hf_gray_16] PIGMENT }

#declare QuickLandscape =
height_field {
    pattern 200, 200 {hf_gray_16 bozo
        color_map { [0 rgb 0] [1 rgb 1] }
    }
}


There are many ways to do it with an isosurface, it depends on what kind 
of terrain you are looking for. You could use the ridged multifractal 
functions(which I have never used and don't know anything about), a 
plane displaced with one or several noise3d() functions, or a plane 
displaced with one or several pigments. Of the last two, mixing pigments 
is more flexible but possibly slower.
An example:

#declare WrinklesFunc =
function {
    pigment {wrinkles
        color_map {[0 color Black][1 color White]}
    }
}

isosurface {
    function {y - // the xy plane...
        WrinklesFunc(x, 0, z)*5 -
        WrinklesFunc(x*3, 0, z*3)*2
        // notice the y value is set to 0
        // If y is used in this part, overhangs
        // are possible.
    }
    threshold 0
}

-- 
Chris Huff
e-mail: chr### [at] yahoocom
Web page: http://chrishuff.dhs.org/

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>
>Well, you can use a height field without an image, using a pattern
>instead. To do that you use the "pattern" keyword. Here is the syntax
>and a sample copied from the MegaPOV documentation:

>
> ...

>

Thanks, I'll experiment a little with that.


--ll

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Thankyou Chris, I hadn't thought of that - more time wasted experimenting!

Mick

--
*************************************************************
       http://www.minda.swinternet.co.uk/index.htm

*************************************************************
"Chris Huff" <chr### [at] yahoocom> wrote in message
news:chrishuff_99-6CC216.11093006032000@news.povray.org...
> In article <38c38e9c@news.povray.org>, "Lars Luthman" <no### [at] spamse>
> wrote:
>
> > Is there a tutorial somewhere on how to create realistic looking
> > mountains in POV without using image files as heightfields (for
> > example using the isosurfaces in MegaPOV)? Or could someone reply to
> > this message and explain the basics?
>
> Well, you can use a height field without an image, using a pattern
> instead. To do that you use the "pattern" keyword. Here is the syntax
> and a sample copied from the MegaPOV documentation:
>
> pattern Width, Height { [ hf_gray_16] PIGMENT }
>
> #declare QuickLandscape =
> height_field {
>     pattern 200, 200 {hf_gray_16 bozo
>         color_map { [0 rgb 0] [1 rgb 1] }
>     }
> }
>
>
> There are many ways to do it with an isosurface, it depends on what kind
> of terrain you are looking for. You could use the ridged multifractal
> functions(which I have never used and don't know anything about), a
> plane displaced with one or several noise3d() functions, or a plane
> displaced with one or several pigments. Of the last two, mixing pigments
> is more flexible but possibly slower.
> An example:
>
> #declare WrinklesFunc =
> function {
>     pigment {wrinkles
>         color_map {[0 color Black][1 color White]}
>     }
> }
>
> isosurface {
>     function {y - // the xy plane...
>         WrinklesFunc(x, 0, z)*5 -
>         WrinklesFunc(x*3, 0, z*3)*2
>         // notice the y value is set to 0
>         // If y is used in this part, overhangs
>         // are possible.
>     }
>     threshold 0
> }
>
> --
> Chris Huff
> e-mail: chr### [at] yahoocom
> Web page: http://chrishuff.dhs.org/

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In article <38c40f7d@news.povray.org>, "Mick Hazelgrove" 
<mha### [at] mindaswinternetcouk> wrote:

> Thankyou Chris, I hadn't thought of that - more time wasted experimenting!

It is only wasted if you didn't learn anything in the process...which I 
doubt is true.

-- 
Chris Huff
e-mail: chr### [at] yahoocom
Web page: http://chrishuff.dhs.org/

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What I should have said was more time messin with Pov when I should be doing
some work!

Mick

--
*************************************************************
       http://www.minda.swinternet.co.uk/index.htm

*************************************************************
"Chris Huff" <chr### [at] yahoocom> wrote in message
news:chrishuff_99-BF59FD.15362506032000@news.povray.org...
> In article <38c40f7d@news.povray.org>, "Mick Hazelgrove"
> <mha### [at] mindaswinternetcouk> wrote:
>
> > Thankyou Chris, I hadn't thought of that - more time wasted
experimenting!
>
> It is only wasted if you didn't learn anything in the process...which I
> doubt is true.
>
> --
> Chris Huff
> e-mail: chr### [at] yahoocom
> Web page: http://chrishuff.dhs.org/

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Mick Hazelgrove wrote:
> 
> What I should have said was more time messin with Pov when I should be doing
> some work!

I still can't see where that would be a problem :)

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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