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In a separate post about flames and media, Dan gave advice for getting a
density of y(1-y) which is attached at the end.
I tried Dan's algorithm and I think that instead I got y^2.
My code is:
interior {
media {
emission rgb 1 //<0.75,0.75,0.75>
intervals 30
samples 10, 10
confidence 0.9999
variance 1/1000
density {
gradient y
translate -y
}
density {
gradient y
}
}
}
Applying this to an object at hand, attached below, I think that you can
see that it clearly looks like y^2, not y(1-y).
-------BEGIN QUOTE FROM DAN CONNELLY----------------
But I can explain densities.
Basically each density statment in series multiplies the net density by
its values.
So
density {
gradient y
}
results in density, over the interval y from 0 to 1, equal to y.
But :
density {
gradient y
}
density {
gradient y
}
results in density, over the interval y from 0 to 1, equal to y^2.
(this would be better done using poly_wave 2)
And,
density {
gradient y
translate -y
}
density {
gradient y
}
yields density of y (1 - y) over the same interval.
So "shaping" the media is a matter of using the densities which
apply the appropriate zero boundary conditions with the appropriate
transitions.
Dan
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Whoops! My fault.....
that should be "translate y", not "translate -y".
I made the classic mistake of translating the observer rather than the
field.... what I want is the interval from (-1,0) to be "boosted" to
(0,1), which requires a +1 translating.
Sorry...
Dan
"Greg M. Johnson" wrote:
>
> In a separate post about flames and media, Dan gave advice for getting a density of
y(1-y) which is attached at the end.
> I tried Dan's algorithm and I think that instead I got y^2.
> My code is:
>
> interior {
> media {
> emission rgb 1 //<0.75,0.75,0.75>
> intervals 30
> samples 10, 10
> confidence 0.9999
> variance 1/1000
> density {
> gradient y
> translate -y
> }
> density {
> gradient y
> }
> }
>
--
http://www.flash.net/~djconnel/
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