We had a visit from some Youtubers today,

(I'm right at the beginning, don't blink, or you'll miss me  :D )
https://www.youtube.com/shorts/u-b6RyFht3s

During the little pow-wow that they had inside our store, Tiger Stacker was
telling alittle story about how he learned to mint his own coined silver rounds,
and at first his weight was off because he neglected to account for the fact
that the coined round wasn't a perfect cylinder, because the designs on the
obverse and reverse are recessed relative to the rim.

Trigger warning:  this may be a shock to some of you.

My mind immediate went to POV-Ray.

There ought to be a neat way to do this using a mesh or heightfield of the
design and a cylinder.

I'm thinking that there should be a way to take a design from a 3D printing
file, or a depth map, or a heightfield, and subtract it from a cylinder and
calculate the volume.

Or just subdivide the regions between the obverse and reverse, and sum the
volumes of the ... whatever shape those "parallelpipeds" are called.

No one needs to implement this - just issuing a call for ideas and different
approaches.
Obviously, I might be able to brute-force it with trace (), but I was wondering
if there was something more efficient and ... elegant.

- BE

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On 16.10.2026 2:49, Bald Eagle wrote:
> We had a visit from some Youtubers today,
> 
> (I'm right at the beginning, don't blink, or you'll miss me  :D )
> https://www.youtube.com/shorts/u-b6RyFht3s
> 
> During the little pow-wow that they had inside our store, Tiger Stacker was
> telling alittle story about how he learned to mint his own coined silver rounds,
> and at first his weight was off because he neglected to account for the fact
> that the coined round wasn't a perfect cylinder, because the designs on the
> obverse and reverse are recessed relative to the rim.
> 
> Trigger warning:  this may be a shock to some of you.
> 
> My mind immediate went to POV-Ray.
> 
> There ought to be a neat way to do this using a mesh or heightfield of the
> design and a cylinder.
> 
> I'm thinking that there should be a way to take a design from a 3D printing
> file, or a depth map, or a heightfield, and subtract it from a cylinder and
> calculate the volume.
> 
> Or just subdivide the regions between the obverse and reverse, and sum the
> volumes of the ... whatever shape those "parallelpipeds" are called.
> 
> No one needs to implement this - just issuing a call for ideas and different
> approaches.
> Obviously, I might be able to brute-force it with trace (), but I was wondering
> if there was something more efficient and ... elegant.
> 
> - BE
> 

Sure there is: open an image you were going to use as a height filed and 
sum all the pixel values together - that will be the "volume" in some 
arbitrary units :-)

Surely I can write a simple thingy in Python for this, but what is it 
good for?

-- 
Ilyich the Toad
https://dnyarri.github.io/

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Ilya Razmanov <ily### [at] gmailcom> wrote:

> Sure there is: open an image you were going to use as a height filed and
> sum all the pixel values together - that will be the "volume" in some
> arbitrary units :-)

Ooh - good point.
Sometimes geometry is simpler than I anticipate!

> Surely I can write a simple thingy in Python for this, but what is it
> good for?

I dunno.
other than the coin application:

Make an upside-down heightfield, subtract it from a landscape to make  lake, and
now can know the volume.

People do all sorts of things with POV-Ray that you can never anticipate.

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On 18.10.2026 1:10, Bald Eagle wrote:
> Ilya Razmanov <ily### [at] gmailcom> wrote:
> 
>> Sure there is: open an image you were going to use as a height filed and
>> sum all the pixel values together - that will be the "volume" in some
>> arbitrary units :-)
> 
> Ooh - good point.
> Sometimes geometry is simpler than I anticipate!
> 

One of my secret superpowers is my capability to use school math for 
image editing ;-)

-- 
Ilyich the Toad
https://dnyarri.github.io/

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