"Bald Eagle" <cre### [at] netscapenet> wrote:
> TOK,
>
> He posted his scene here :
>
http://news.povray.org/povray.general/attachment/%3Cweb.63d236cb249f00761ffa55cd10800fb2%40news.povray.org%3E/surface
3.
> pov.txt

Yes, I saw that. Thank you.


> I'm not sure how the data is generated from MatLab in order to be exported to
> triangles for POV-Ray, but I'm thinking that it might be better to export the
> geometry for the mesh separately, and then run a macro in POV-Ray to calculate
> the normals and color interpolation - or use the gradient y pigment.

Yes, that may be a possible way to go. But could it not be that some
would want to verify that their Matlab code generates ok normals and
colors ?


> I'm guessing that the normals are probably ok (?) and it's just the hard-coded
> colors getting interpolated that throws it all off.
>
> I'd have to dig through it all to see - but after I just did some more sorting
> macro stuff to handle the function timing (other thread), maybe I could try to
> sort the triangle vertices into a grid so that they can be put into a 2D array
> and then reprocessed.
>
> Purely as a sorting macro exercise for myself, which might prove useful to
> someone else int he future.

Are you thinking of sorting and collecting all the vertices into
a list of unique vertices ?

If so, it would be an interesting challenge to simultaneously
rearrange the colors and the normal vectors so that they are ordered
correspondingly (or respectively ?) in their own lists.

--
Tor Olav
http://subcube.com
https://github.com/t-o-k

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"Bald Eagle" <cre### [at] netscapenet> wrote:
> "Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:
>
> > Hi
>
> Hi yourself.
>
> > Have you not yet met Emacs?
> >
> >   ;-)
>
> Nope.   I was raised in the American Public Education System, where we're
> supposed to be just smart enough to read the names of the puppets that they
> nominate every cycle, and not smart enough to undo the shackles and escape the
> matrix.  As such, I still have certain  -  disabilities.
>
> > See the attached zip-file.
> >
> > --
> > Tor Olav
>
> I had a feeling that Mr. Wizard would appear, with something out of his bag of
> tricks.  :D

Hehe - I don't feel like a wizard. But during the years I have
become familiar with a few magic wands, like for example Emacs.


> I truly do need to sit down and work with Emacs, Vim, awk, etc and figure out
> how to do all the "word processing" tricks.

You can teach Emacs a lot of tricks with keyboard macros and
scripts. And you can even rearrange your keyboard to work the
way you like, e.g. by binding scripts to keys.

And then you can program Emacs in lisp. But have not looked
into that (yet).

So I recommend joining the Church of Emacs!

I really don't like vi and vim.
- They are the work of The Evil One ;-)

On several occasions I've found sed and awk/gawk useful.


> Thanks for being right there with a ready-made array example.

No problem.

--
Tor Olav
http://subcube.com
https://github.com/t-o-k

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"jr" <cre### [at] gmailcom> wrote:
> hi,
>
> "Bald Eagle" <cre### [at] netscapenet> wrote:
> > ...
> > I truly do need to sit down and work with Emacs, Vim, awk, etc and figure out
> > how to do all the "word processing" tricks.
>
> if your after-tax earnings allow :-), there's O'Reilly's excellent 'sed & awk',
> by Dougherty & Robbins.

I once spent several months using gawk to process logs from the
Linux kernel on an embedded CPU board to find out what was causing
an intermittent problem with an Ethernet port while it was booting.
(The Ethernet port did not show up in about one of hundred boots.)

Some months later I started learning Python and found that it
provides much better text processing tools than awk (although
some of them are similar) and was much easier to use for such
tasks.

So now I very much regret that I didn't look into Python earlier.
If I had not been so stubborn sticking to C, Pascal, Basic,
assembly and Excel, I would have saved a LOT of time in the past.

--
Tor Olav
http://subcube.com
https://github.com/t-o-k

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"yesbird" <nomail@nomail> wrote:
> Hi, Tor.
> >
> > Have you not yet met Emacs?
> >
> >   ;-)
>
> Already no, I leaved it about 10 years ago. )

What ?
Didn't you want to be saved ?
You can still join the congregation...


> > See the attached zip-file.
> You are the wizard - what a beauty those normals !
> Thanks a lot - this is another piece of code for embedding.

You're welcome.

Instead of #declaring a vertex, normal and color on each line,
like this:

#declare I = I + 1;
#declare VV[I][0] = <3.43, 7.67, 1.83>;
#declare NN[I][0] = <0.32, 0.72, 0.62>;
#declare VV[I][1] = <3.76, 7.67, 1.63>;
#declare NN[I][1] = <0.36, 0.74, 0.56>;
#declare VV[I][2] = <3.76, 8.00, 1.13>;
#declare NN[I][2] = <0.37, 0.78, 0.51>;
#declare Colors[I][0] = <0.43, 1.00, 0.00>;
#declare Colors[I][1] = <0.48, 1.00, 0.00>;
#declare Colors[I][2] = <0.62, 1.00, 0.00>;
....

I think it would be better if your Matlab code created the arrays
containing the vectors directly, like this:

#declare VV =
    array[N][3] {
        { <3.43, 7.67, 1.83>, <3.76, 7.67, 1.63>, <3.76, 8.00, 1.13> },
        ...
    }
;
#declare NN =
    array[N][3] {
        { <0.32, 0.72, 0.62>, <0.36, 0.74, 0.56>, <0.37, 0.78, 0.51> },
        ...
    }
;
#declare Colors =
    array[N][3] {
        { <0.43, 1.00, 0.00>, <0.48, 1.00, 0.00>, <0.62, 1.00, 0.00> },
        ...
    }
;

--
Tor Olav
http://subcube.com
https://github.com/t-o-k

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hi,

"Bald Eagle" <cre### [at] netscapenet> wrote:
> ...
> Just went small-scale food shopping, and the prices on some things are
> completely ridiculous.

yes, same this side of pond.  _and_ the packages contain less product.


> But if I get that, then I will have at least TWO computer books!  :D

that would be good.  you could read one while the other still props up the
kitchen table ;-).


regards, jr.

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hi,

"Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:
> ...
> So now I very much regret that I didn't look into Python earlier.

if BE had mentioned 'Tcl', I would have recommended that.  he did mention 'vim',
but I didn't want to get into the .. religious arguments ;-).

re Python, does "sed -e 's#^I# #g' -i *.py" still work for newer versions of the
language ?!  :-)


regards, jr.

Post a reply to this message

> What ?
> Didn't you want to be saved ?
> You can still join the congregation...

O, thanks, but egrep, sed, awk, sort and python are taking care about my soul.
Before python era perl also did that, but now he is gone ...

> I think it would be better if your Matlab code created the arrays
> containing the vectors directly, like this:
>
> #declare VV =
>     array[N][3] {
>         { <3.43, 7.67, 1.83>, <3.76, 7.67, 1.63>, <3.76, 8.00, 1.13> },
>         ...
>     }
> ;

Exactly ! This is much more compact and readable, thanks again.
Now I am going to study POV magic, especially macros, more seriously.

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"jr" <cre### [at] gmailcom> wrote:
> "Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:
> > ...
> > So now I very much regret that I didn't look into Python earlier.
> ...
> re Python, does "sed -e 's#^I# #g' -i *.py" still work for newer versions of the
> language ?!  :-)

might be perceived .. rude.  but that, really, is not intended.  I do think that
'make', when conceived, ought not to have made its functioning dependent on an
"invisible" (ie 0x09) character.  and I cannot understand to this day why, with
that "experience" in mind, someone would want to design a new, "system-level"
even, language which relies (relied?) on the same not-visible control character.


regards, jr.

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"Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:

> Are you thinking of sorting and collecting all the vertices into
> a list of unique vertices ?
>
> If so, it would be an interesting challenge to simultaneously
> rearrange the colors and the normal vectors so that they are ordered
> correspondingly (or respectively ?) in their own lists.


Well, the idea was, given the "point cloud", and the fact that it's obviously
generated in a grid layout, then I should be able to sort by multiple fields -
x, then z.  That would all go into a 2D array.  And yes, the normals and colors
would go into the same array.

Post a reply to this message

"Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:

> I think it would be better if your Matlab code created the arrays
> containing the vectors directly, like this:
>
> #declare VV =
>     array[N][3] {
>         { <3.43, 7.67, 1.83>, <3.76, 7.67, 1.63>, <3.76, 8.00, 1.13> },
>         ...
>     }
> ;
> #declare NN =
>     array[N][3] {
>         { <0.32, 0.72, 0.62>, <0.36, 0.74, 0.56>, <0.37, 0.78, 0.51> },
>         ...
>     }
> ;
> #declare Colors =
>     array[N][3] {
>         { <0.43, 1.00, 0.00>, <0.48, 1.00, 0.00>, <0.62, 1.00, 0.00> },
>         ...
>     }
> ;

I would go one step further, and put them all into the same array, although
that's not strictly necessary.   I'm just thinking about juggling all of the
data in a macro, and having a single array name would make it easier, but not
really necessary.

But also, depending on what other people might want to do with the data, if it
were a [N][9] array, then the ASCII format would lend itself to importing into a
spreadsheet and keeping all of that data together.   It would also be together
in the ASCII SDL/inc file, so that it would be easy to read and think about,
rather than hunting through 3 arrays.  Making it a [N][10] array would allow
numbering of the vertices as well, and for the same easy-reading purpose.

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