is there any simple way to let povray calculate the surface area and volume
of an object?
For example, for a buoy, whose mass depends on it's surface area, it's
displacement beneath the water surface could be calculated very easily if
there were functions to calculate the volume & surface area of the buoy in
povray.
of course I could calculate this manually also, but it would be a lot easier
if povray could do this.


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Q: How many mathematicians does it take to screw in a light bulb?
A: One.  He gives it to six Californians, thereby reducing the problem
 to the earlier joke.

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In article <41ba0d45@news.povray.org>,
 Samuel Hoffstaetter <sho### [at] gmailcom> wrote:

> is there any simple way to let povray calculate the surface area and volume
> of an object?
> For example, for a buoy, whose mass depends on it's surface area, it's
> displacement beneath the water surface could be calculated very easily if
> there were functions to calculate the volume & surface area of the buoy in
> povray.
> of course I could calculate this manually also, but it would be a lot easier
> if povray could do this.

There is no easy, general method for doing so, and for some objects 
there are multiple ways to define "surface area". For example, do you 
count both sides of a triangle? Do you count the inner surface of an 
open-ended cylinder? And how do you compute the area of a julia fractal? 
Volume also has some problems...not all shapes have a finite volume, and 
how do you define it for open objects?

However, given some knowledge about the object, you can use the 
scripting capabilities of the POV-Ray scene description language to get 
a numeric approximation. It should be pretty easy to compute both 
surface area and volume for a more or less cylindrical shape with a few 
loops and trace() calls, for example.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/

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Christopher James Huff wrote:

> In article <41ba0d45@news.povray.org>,
>  Samuel Hoffstaetter <sho### [at] gmailcom> wrote:
> 
>> is there any simple way to let povray calculate the surface area and
>> volume of an object?
>> For example, for a buoy, whose mass depends on it's surface area, it's
>> displacement beneath the water surface could be calculated very easily if
>> there were functions to calculate the volume & surface area of the buoy
>> in povray.
>> of course I could calculate this manually also, but it would be a lot
>> easier if povray could do this.
> 
> There is no easy, general method for doing so, and for some objects
> there are multiple ways to define "surface area". For example, do you
> count both sides of a triangle? Do you count the inner surface of an
> open-ended cylinder? And how do you compute the area of a julia fractal?
> Volume also has some problems...not all shapes have a finite volume, and
> how do you define it for open objects?
>

too bad :-( 

> However, given some knowledge about the object, you can use the
> scripting capabilities of the POV-Ray scene description language to get
> a numeric approximation. It should be pretty easy to compute both
> surface area and volume for a more or less cylindrical shape with a few
> loops and trace() calls, for example.
> 

thanks.


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You will be misunderstood by everyone.

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