There's a thread on Access97 in p.o-t. 
Gilles gets data from databases and renders these with POV-Ray.
I'm playing a bit with SQLite to get an idea of SQL. 

SQLite is a relative simple tool that can be used from the commandline but 
is designed to be embedded in an other application.

So,
how usefull would it be to have an embedded database in POV-Ray? What kind 
of things could one do then? Could it be helpfull for particle systems? 
Could it be helpfull for keeping persistent data between rendering frames 
of an animation?

http://www.sqlite.org/

Ingo

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"ingo" <ing### [at] tagpovrayorg> wrote in message
news:Xns9597D61F45BD9seed7@news.povray.org...

<snip>

Could be fun - can someone remind me, can pov construct and execute external
commands?

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"Tom Melly" <pov### [at] tomandlucouk> wrote:

> <snip>
>
> Could be fun - can someone remind me, can pov construct and execute external
> commands?

Hi,

I don` t know.

but you could write a file (command.txt) with povray, with just one line:

myprogram.exe

-----------
Then you run a small programm in wxbasic or whatever:

//--------------- pseudocode

while(1)
 fopen command.txt as #1
  line input thecommand
  if right(thecommand,3) = "exe" then
   shell(thecommand) //-- execute the line as an external program
  end
 fclose #1
 deletefile("command.txt") //-- delete file to avoid repeated execution
 sleep(5)
end while

//-- end ---------- pseudocode

Greets, Mark

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Xns9597D61F45BD9seed7@news.povray.org...
> So,
> how usefull would it be to have an embedded database in POV-Ray? What kind
> of things could one do then? Could it be helpfull for particle systems?
> Could it be helpfull for keeping persistent data between rendering frames
> of an animation?

I have wondered several times about a built-in ODBC connectivity in the SDL 
(rather than an embedded database). I guess a lot of code for that is 
already in the PHP source. About possible uses, the way I'm using an 
Oracle/Access/POV-Ray 3.1 combo is fairly atypical but being able to store 
things in databases is always handy, particularly in the scientific / 
technical field. Coupled with a good SDL library for charts and graphs that 
could be interesting for people who are into scientific visualisation.

G.


-- 
**********************
http://www.oyonale.com
**********************
- Graphic experiments
- POV-Ray and Poser computer images
- Posters

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"ingo" <ing### [at] tagpovrayorg> wrote in message
news:Xns9597D61F45BD9seed7@news.povray.org...
[deletions]
: how usefull would it be to have an embedded database in POV-Ray? What kind
: of things could one do then? Could it be helpfull for particle systems?
: Could it be helpfull for keeping persistent data between rendering frames
: of an animation?

I made a Pov 3.1 version that had dBASE III read and write
capability. I posted an article about it offering the patch but
no one answered. I threw it out after about a year and there
was absolutely no interest.
=Bob=

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> So,
> how usefull would it be to have an embedded database in POV-Ray? What kind 
> of things could one do then? Could it be helpfull for particle systems? 
> Could it be helpfull for keeping persistent data between rendering frames 
> of an animation?

As Mark already mentioned, POV has its own file I/O. IMHO we don't need 
a database support with POV-Ray, but better file I/O. Right now, it's 
limited to comma-seperated values, and IIRC some of them are also 
automagically parsed, etc. I'd like to have a file I/O which at least 
lets me read in a text file line by line (returning the whole line as a 
string).

If you add a exec-command (to execute external programs), it would 
enable us to write the database support as a inc-file, a method which I 
would prefer (not dependant on database-type, etc.). Of course 
introducing an exec-command creates a big new potential for malicious 
pov scripts. So there should be perhaps some restrictive options on that 
command, like we have the I/O-restrictions right now.

Better file-I/O could be the key to a lot more interesting plugins for 
POV in include-files (as opposed to patches). Things like 
file-format-converters, analytical stuff, etc. And as far as it's 
strings only, it would also be pretty portable, aside from the line 
endings, of course.


Just my 0.02$
Florian
-- 
camera{look_at-y*10location<8,-3,-8>*10}#local a=0;#while(a<999)sphere{
#local _=.01*a-4.99;#local p=a*.01-5;#local c=.01*a-4.995;<sin(p*pi)*5p
*10pow(p,5)*.01>sin(c*c*c*.1)+1pigment{rgb 3}}#local a=a+1;#end
/******** http://www.torfbold.com ******** http://www.imp.org ********/

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Tom Melly wrote:

> "ingo" <ing### [at] tagpovrayorg> wrote in message
> news:Xns9597D61F45BD9seed7@news.povray.org...
> 
> <snip>
> 
> Could be fun - can someone remind me, can pov construct and execute external
> commands?
> 
> 
Like invoking a program?  Don't think so.  I believe the last time the 
question can up, the answer was: start with the external program and us 
it to invoke POV.

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In article <418ab6a5@news.povray.org>, "=Bob=" 
<robertUNDERSCOREdobbinsATmailDOTtdsDOTnet> says...
> "ingo" <ing### [at] tagpovrayorg> wrote in message
news:Xns9597D61F45BD9seed7@news.povray.org...
> [deletions]
> : how usefull would it be to have an embedded database in POV-Ray? What kind
> : of things could one do then? Could it be helpfull for particle systems?
> : Could it be helpfull for keeping persistent data between rendering frames
> : of an animation?
> 
> I made a Pov 3.1 version that had dBASE III read and write
> capability. I posted an article about it offering the patch but
> no one answered. I threw it out after about a year and there
> was absolutely no interest.

Too bad.. Unfortunately making something and convincing them it is useful 
is not always the same thing. You sometimes have to show them how useful 
it is in a significant way. I am more the "any thing that makes like 
easier" sort and I can see that as a feature with would make some things 
easier.

-- 
void main () {

    call functional_code()
  else
    call crash_windows();
}

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In article <418ac51b$1@news.povray.org>, tor### [at] torfboldcom says...
> > So,
> > how usefull would it be to have an embedded database in POV-Ray? What kind 
> > of things could one do then? Could it be helpfull for particle systems? 
> > Could it be helpfull for keeping persistent data between rendering frames 
> > of an animation?
> 
> As Mark already mentioned, POV has its own file I/O. IMHO we don't need 
> a database support with POV-Ray, but better file I/O. Right now, it's 
> limited to comma-seperated values, and IIRC some of them are also 
> automagically parsed, etc. I'd like to have a file I/O which at least 
> lets me read in a text file line by line (returning the whole line as a 
> string).
> 
Except databases go beyond simple I/O. For instance, a smart system could 
read in the contents of a .inc file to the database (or the equivalent), 
which will only be used in an animation in say 50 frames out of 100, then 
only read that back in from the DB 'when' it is needed, rather than 
parsing the entire file each time. I suspect that is a bit harder to 
manage currently, if it is even possible. It would be nice to let the SDL 
do most of the work and not have to rely on external applications that 
often don't cover 100% of all the things you need them to. This is 
especially true of custom built applications, since they are likely 
designed to only do one thing at a time, making them nice for the 
designer, but more or less useless for the community. unless of course it 
is one of those: Use program A to generate part X, program B to make part 
Y, program C to make part Z and then use program D to hopefully produce 
the SDL. Gives me a headache just thinking about it. ;)

-- 
void main () {

    call functional_code()
  else
    call crash_windows();
}

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In article <Xns9597D61F45BD9seed7@news.povray.org>,
 ingo <ing### [at] tagpovrayorg> wrote:

> how usefull would it be to have an embedded database in POV-Ray? What kind 
> of things could one do then? Could it be helpfull for particle systems? 
> Could it be helpfull for keeping persistent data between rendering frames 
> of an animation?

I don't see why it would be any better than simply allowing the user to 
keep a data structure for the next frame. What benefit does a database 
give you?

No, it wouldn't benefit particle systems. A general database system 
would be too slow for that kind of thing.

However, some more versatile data structures (easily modifiable arrays, 
lists, sets, and dictionaries) would be very useful. Also things like 
point sets and other more specialized structures...

-- 
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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