The black dots represent unpainted background due to a mismatch between the
(for latitude: for longitude:) iteration over the grain of the original map
with the projected coordinates of the viewport.  In other words, no cell on
the original map reprojected right on that pixel.  Adding a tilt or twist
seems to make this problem worse.  Cheap fixes include post-processing to
smooth away black pixels within the disk, or chopping up the original map
into more identically colored adjacent pixels to give a finer grain and
higher likelihood of painting all the pixels in the disk.

The right thing to do is probably to code up a reverse projection from "disk
view" space back to "map" space and iterate over pixels within the disk so
that nothing in the disk view remains unpainted.

---

According to the web site note, the maps are individually available for
re-use according to various terms -- probably a "credit given" , but I
haven't written to the site owner yet.  Let me do that tomorrow (after I
sleep and collect my wits, before I go out of town again for part 2 of my
vacation week).

"Most of these maps below are slightly "tweaked" from public domain maps;
some are based on maps/data which should also be credited to the original
authors (even if public domain, they deserve credit), so please contact me
regarding redistribution, commercial use, etc." -- Wm. Robert Johnson.

So in some cases I could go back to William Robert Johnson's sources, or I
could just see if some kind of credit is appropriate.  Does Thousand Parsec
have an official "About" or "Credits" section?

-- Jeff

On Mon, Aug 18, 2008 at 7:04 PM, Tim Ansell <[EMAIL PROTECTED]> wrote:

> Hey jsmiller,
>
> That looks pretty cool. Where are the black dots coming from?
>
> Do you know what license these files are under? If they are public
> domain it would be good to add them to our repository.
>
> Tim
>
> On Wed, 2008-08-13 at 22:48 -0700, Jeffrey Miller wrote:
> > Follow-up:  I found some cylindrical projection planetary maps here:
> >
> >    http://www.johnstonsarchive.net/spaceart/cylmaps.html
> >
> > which seem to work well as textures, allowing for some missing data.
> > Attached is an example of a reprojected Jupiter disk.
>
>
>
> _______________________________________________
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> [email protected]
> http://www.thousandparsec.net/tp/mailman.php/listinfo/tp-devel
>
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