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function {1f_cylindrical(x,y,z)}
How do I make it so that the density decreases exponentially?
Simply this?
function {1f_cylindrical(x,y,z)*f_cylindrical(x,y,z)}
Thanks.
Mike
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On 2/6/2021 11:48 PM, Mike Horvath wrote:
> I am using this density function:
>
> function {1f_cylindrical(x,y,z)}
>
> How do I make it so that the density decreases exponentially?
>
> Simply this?
>
> function {1f_cylindrical(x,y,z)*f_cylindrical(x,y,z)}
>
> Thanks.
>
>
> Mike
Increases rather.
Mike
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Mike Horvath <mik### [at] gmailcom> wrote:
> On 2/6/2021 11:48 PM, Mike Horvath wrote:
> > I am using this density function:
> >
> > function {1f_cylindrical(x,y,z)}
> >
> > How do I make it so that the density decreases exponentially?
> Increases rather.
> > function {1f_cylindrical(x,y,z)*f_cylindrical(x,y,z)}
This would be geometrically?
Exponentially would imply using log() or (exp) ?
or maybe pow (term, some varying power)
I usually use a spreadsheet, or plot my function in POVRay with spheres to show
myself what's actually going on
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Le 20210207 à 09:07, Bald Eagle a écrit :
>
> Mike Horvath <mik### [at] gmailcom> wrote:
>> On 2/6/2021 11:48 PM, Mike Horvath wrote:
>>> I am using this density function:
>>>
>>> function {1f_cylindrical(x,y,z)}
>>>
>>> How do I make it so that the density decreases exponentially?
>> Increases rather.
>
>
>>> function {1f_cylindrical(x,y,z)*f_cylindrical(x,y,z)}
>
> This would be geometrically?
>
> Exponentially would imply using log() or (exp) ?
> or maybe pow (term, some varying power)
>
> I usually use a spreadsheet, or plot my function in POVRay with spheres to show
> myself what's actually going on
>
>
function {1f_cylindrical(x,y,z)*f_cylindrical(x,y,z)}
is exactly the same as
function {1pow(f_cylindrical(x,y,z),2)}
The advantage of the second is that f_cylindrical need to be evaluated
only once, making the evaluation of the whole function faster.
An exponential curve could be something like :
function {1 exp(f_cylindrical(x,y,z))}
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On 2/7/2021 9:07 AM, Bald Eagle wrote:
> This would be geometrically?
>
Dunno what you mean.
> Exponentially would imply using log() or (exp) ?
> or maybe pow (term, some varying power)
>
> I usually use a spreadsheet, or plot my function in POVRay with spheres to show
> myself what's actually going on
>
>
Which would be better for planet atmosphere density? I used `pow` but is
`exp` better?
Mike
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On 2/8/2021 10:24 AM, Alain Martel wrote:
> The advantage of the second is that f_cylindrical need to be evaluated
> only once, making the evaluation of the whole function faster.
>
Good tip, thanks! Any speed improvement is important.
Mike
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Mike Horvath <mik### [at] gmailcom> wrote:
> On 2/7/2021 9:07 AM, Bald Eagle wrote:
> > This would be geometrically?
> Dunno what you mean.
Doesn't matter  I think they're the same.
> Which would be better for planet atmosphere density? I used `pow` but is
> `exp` better?
https://en.wikipedia.org/wiki/Density_of_air#Variation_with_altitude
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On 2/8/2021 6:52 PM, Bald Eagle wrote:
> Mike Horvath <mik### [at] gmailcom> wrote:
>> On 2/7/2021 9:07 AM, Bald Eagle wrote:
>>> This would be geometrically?
>> Dunno what you mean.
>
> Doesn't matter  I think they're the same.
>
>
>> Which would be better for planet atmosphere density? I used `pow` but is
>> `exp` better?
>
> https://en.wikipedia.org/wiki/Density_of_air#Variation_with_altitude
>
>
>
>
I'm not very good at math so I don't know how to translate that into
something POVRay can consume.
Mike
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