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I want a band of mountains on the horizon that drop to foothills and finally
a plane as z approaches 0.
#declare MountFunc = function {"ridgedMF" <1,5,3,1/3,50>}
with
function{ y + (MountFunc(x*z,0,z)*5)} // (note the x*z)
doesn't work. While the mountains become less prounounced, the plane is at
the level of the highest peak rather than the foothills.
As a kludge, function{sqr(y) + sqr(z) + (MountFunc(x,0,z)*5)} is okay with a
separate shape for the plane, but I would prefer option a).
Any ideas?
BTW has anyone got any samples of good parameters for ridged mf?
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Tom Melly wrote:
>
> I want a band of mountains on the horizon that drop to foothills and finally
> a plane as z approaches 0.
>
> #declare MountFunc = function {"ridgedMF" <1,5,3,1/3,50>}
> with
> function{ y + (MountFunc(x*z,0,z)*5)} // (note the x*z)
>
> doesn't work. While the mountains become less prounounced, the plane is at
> the level of the highest peak rather than the foothills.
>
Try this:
function{ y - (MountFunc(x*z,0,z)*5)}
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In article <3aacfffc$1@news.povray.org>, "Tom Melly"
<tom### [at] tomandlu co uk> wrote:
> I want a band of mountains on the horizon that drop to foothills and
> finally a plane as z approaches 0.
>
> #declare MountFunc = function {"ridgedMF" <1,5,3,1/3,50>}
> with
> function{ y + (MountFunc(x*z,0,z)*5)} // (note the x*z)
Try: function {y - MountFunc(x,0,z)*5*min(0, z)}
You were multiplying the x coordinate by z, translating the function by
an amount dependant on the distance along the x and z axis. The version
I gave scales the values returned by the function by an amount dependant
on the z axis, which is what I think you wanted. Also, you subtract from
y to raise the height of the plane...your "mountains" were sinking below
ground level, not rising above it.
The "min(0, z)" prevents "negative" mountains falling off in the -z
direction.
--
Christopher James Huff
Personal: chr### [at] mac com, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tag povray org, http://tag.povray.org/
<><
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Tom Melly wrote:
>
> I want a band of mountains on the horizon that drop to foothills and finally
> a plane as z approaches 0.
>
> #declare MountFunc = function {"ridgedMF" <1,5,3,1/3,50>}
> with
> function{ y + (MountFunc(x*z,0,z)*5)} // (note the x*z)
>
> doesn't work. While the mountains become less prounounced, the plane is at
> the level of the highest peak rather than the foothills.
>
> As a kludge, function{sqr(y) + sqr(z) + (MountFunc(x,0,z)*5)} is okay with a
> separate shape for the plane, but I would prefer option a).
>
> Any ideas?
I have once used:
#declare RMFx=function{ "ridgedMF", <0.1, 3.1, 8, 0.7, 0.8> }
#declare Mountains_01=
isosurface{
function{z-RMFx(x,y-0.15,0)*sqrt(1.1-y)*0.4}
method 2
max_gradient 7
accuracy 0.0001
contained_by{box{<-1.7, -1.7, -0.1>, <1, 1, 1>}}
}
Note that z is upwards in this case.
>
> BTW has anyone got any samples of good parameters for ridged mf?
something else I used sometime:
function{ "ridgedMF", <0.1, 2.7, 7, 0.75, 0.7> }
found in this group and p.t.s-f:
function { "ridgedmf", <1,2,10,1.1,2> }
function { "ridgedMF", <1,2,5,0.5,10> }
function { "ridgedmf", <0.95,1.2,8,0.9,20> }
function { "ridgedmf", <0.3, 4, 6, 0.45, 1.9> }
Christoph
--
Christoph Hormann <chr### [at] gmx de>
IsoWood include, radiosity tutorial, TransSkin and other
things on: http://www.schunter.etc.tu-bs.de/~chris/
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Chris Huff schrieb in Nachricht ...
>In article <3aacfffc$1@news.povray.org>, "Tom Melly"
><tom### [at] tomandlu co uk> wrote:
>
>> I want a band of mountains on the horizon that drop to foothills and
>> finally a plane as z approaches 0.
>>
>> #declare MountFunc = function {"ridgedMF" <1,5,3,1/3,50>}
>> with
>> function{ y + (MountFunc(x*z,0,z)*5)} // (note the x*z)
>
>Try: function {y - MountFunc(x,0,z)*5*min(0, z)}
Should be max(0,z), no? Else you would only get negative z.
Marc-Hendrik
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In article <3aad1c0f@news.povray.org>, "Marc-Hendrik Bremer"
<Mar### [at] t-online de> wrote:
> >Try: function {y - MountFunc(x,0,z)*5*min(0, z)}
> Should be max(0,z), no? Else you would only get negative z.
It should...and I *thought* "max(0, z)", I don't know why I typed that.
--
Christopher James Huff
Personal: chr### [at] mac com, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tag povray org, http://tag.povray.org/
<><
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Many, many thanks to all for some extremely useful info, help and tips. God,
I love these groups.
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Tom Melly wrote:
>
> Many, many thanks to all for some extremely useful info, help and tips. God,
> I love these groups.
Thanks isn't enough, show us image! ;o)
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"Vahur Krouverk" <vah### [at] aetec ee> wrote in message
news:3AAD2F01.B12145A9@aetec.ee...
> Thanks isn't enough, show us image! ;o)
My pleasure - "For Vahur" in images ;)
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