Bob,

It's been a while since I wrote eclipse.pov -- some of the details are still
coming back to me.

I had a closer look at your picture 'eclipse.jpg'.

It looks good to me - a penumbral eclipse of the moon might pass unnoticed,
depending on how far into the penumbra the Moon travels.

I can see a little bit of shadow on the lower edge of the Moon. Maybe this
is all we're supposed to see.

And of course for a lunar eclipse it should be opposite what I said before.
The Earth should be between the Sun and Moon, but if you raised the camera
out of the ecliptic you can see both with the Moon in the distance.

You could try commenting out sun2 and the tiny moon (if you haven't already
done so) as they only help in solar eclipses. Removing sun2 will make the
shadow on the Moon a bit darker.

Sorry about the bum steer ...

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"pavium" <jrc### [at] tpgcomau> wrote in message 
news:web.4416b350181997a3e8faad540@news.povray.org...
>
> a penumbral eclipse of the moon might pass unnoticed
> I can see a little bit of shadow on the lower edge of the Moon.

Yep. This one tonight, for the eastern US where I live, isn't going to look 
like much. Should just be dimmed on the righthand side judging by this 
eclipse.pov rendering. I see Australia is opposite the Moon at the time it 
happens, unlucky for you maybe, but you won't be missing this I'm sure.

> And of course for a lunar eclipse it should be opposite what I said 
> before.
> The Earth should be between the Sun and Moon, but if you raised the camera
> out of the ecliptic you can see both with the Moon in the distance.

Adding a second satellite (along with the few necessary parameters) seems to 
work okay, making it look past the Earth. But for now it's just there for 
today's date so I'm sure it would need merging into the other calculating 
somehow.

> You could try commenting out sun2 and the tiny moon (if you haven't 
> already
> done so) as they only help in solar eclipses. Removing sun2 will make the
> shadow on the Moon a bit darker.

Yeah, since that rendering I did comment out the secondary tiny moon, mainly 
because I wasn't sure how it fit into the scene and didn't want to bother 
figuring it out while I was having that peculiar lighting of the Earth. 
Found out I was probably using incompatible image maps so I removed the 
clouds altogether and put in a somewhat large jpeg of the Earth instead. 
After that I changed sun2 into a spotlight pointing at the Earth and reduced 
its brightness considerably so it wouldn't illuminate the Moon. That helped 
darken the shadow.

Most interesting to me is that stuff about locating a place along the 
alignments, so unless I give up trying to understand it I *might* learn 
something.

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pavium wrote:
> It looks like I'll have to invest in some hardware which will run POVRay
> once more. I have actually tried running POVRay on a 75MHz Pentium under
> OpenBSD with no graphics capability. It actually generated 25x80 ASCII text
> images onscreen while saving GIF files to disk. It was fascinating to watch
> but only marginally faster than watching grass grow.


Oh come on, I originally ran POV on a 486 with NO math coprocessor! 
Think of that - all that double precision math being emulated by the 
integer units!  IIRC, it would draw an RSOCP at ~20-30 pps.  Imagine how 
excited I was when I got my first 486 DX, and saw POV running at speeds 
of 100pps or more! :)

...Chambers

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Chambers <bdc### [at] yahoocom> wrote:
> Oh come on, I originally ran POV on a 486 with NO math coprocessor!
> Think of that - all that double precision math being emulated by the
> integer units!  IIRC, it would draw an RSOCP at ~20-30 pps.  Imagine how
> excited I was when I got my first 486 DX, and saw POV running at speeds
> of 100pps or more! :)

486? You were lucky to have a 486! We used to do the calculations by
counting on our fingers, with one arm tied behind our backs and no toes.
Half the fingers were missing, with someone playing old Monty Python
sketches to distract us!

But you try and tell the young people today that... and they won't believe
ya.

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Chambers <bdc### [at] yahoocom> wrote:
> Oh come on, I originally ran POV on a 486 with NO math coprocessor!
> Think of that - all that double precision math being emulated by the
> integer units!  IIRC, it would draw an RSOCP at ~20-30 pps.  Imagine how
> excited I was when I got my first 486 DX, and saw POV running at speeds
> of 100pps or more! :)

I can beat that. I first ran POV on an 8 MHz ARM2 processor in an old Acorn
Archimedes... (which many of you have probably never heard of!). My first
speed upgrade would have been the 33MHz ARM6 in the (slightly) newer Acorn
RiscPC. Neither machine had a co-processor, floating-point calculations
were by software emulation only. Test renders ran like continental drift...
:)

Bill

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