"Justace Clutter" <pro### [at] corpranetnet> wrote in message
news:3db62bce@news.povray.org...
> I am trying to get render a frame with a wave function built in it.  The
> function is the specific solution after seperation of variables was done.
> Anyway all that is irrelelvant.  When I try to render the frame it just
> sits there and does nothing.  the povray process accums time but does not
> do anyhing and I have to kill it with a sig 9 to get it to exit.  I use
> Linux if you have not already guessed.  Any information on this would be
> wonderfull.

Maybe more information given first... Have you narrowed it down to just the
isosurface causing the problem. I recall rendering incredibly slow
isosurfaces, for whatever the reason about them, which I'd have thought
wasn't rendering anything.

If you post the isosurface part of your scene file, if that is all that
could be the problem, then it might help people offer advice about it.

I don't know how the Linux one differs but if it can crash the program and
not show a sign of error then something could be wrong with POV itself. But
maybe it's sort of looping on some calculation.
--
Farewell,
Bob

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In article <3db62bce@news.povray.org> , Justace Clutter 
<pro### [at] corpranetnet>  wrote:

> I am trying to get render a frame with a wave function built in it.  The
> function is the specific solution after seperation of variables was done.
> Anyway all that is irrelelvant.  When I try to render the frame it just
> sits there and does nothing.  the povray process accums time but does not
> do anyhing and I have to kill it with a sig 9 to get it to exit.  I use
> Linux if you have not already guessed.  Any information on this would be
> wonderfull.

Please do not post attachments in these groups.  If your scene is short,
just put it in the message body.  Attachments belong in "binaries" or "text"
groups.  Please do not multi-post either.

Please read the messages in povray.anncounce.frequently-asked-questions for
posting guidelines in these groups.

As far as you problem is concerned, remember that ray-tracing can take very
long.  It is unlikely that POV-Ray just runs and does nothing.  You may want
to turn verbose progress reporting on (read the manual if you don't know how
to do this).

    Thorsten

____________________________________________________
Thorsten Froehlich
e-mail: mac### [at] povrayorg

I am a member of the POV-Ray Team.
Visit POV-Ray on the web: http://mac.povray.org

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hughes, b. wrote:

> "Justace Clutter" <pro### [at] corpranetnet> wrote in message
> news:3db62bce@news.povray.org...
>> I am trying to get render a frame with a wave function built in it.  The
>> function is the specific solution after seperation of variables was done.
>> Anyway all that is irrelelvant.  When I try to render the frame it just
>> sits there and does nothing.  the povray process accums time but does not
>> do anyhing and I have to kill it with a sig 9 to get it to exit.  I use
>> Linux if you have not already guessed.  Any information on this would be
>> wonderfull.
> 
> Maybe more information given first... Have you narrowed it down to just
> the isosurface causing the problem. I recall rendering incredibly slow
> isosurfaces, for whatever the reason about them, which I'd have thought
> wasn't rendering anything.
> 
> If you post the isosurface part of your scene file, if that is all that
> could be the problem, then it might help people offer advice about it.
> 
> I don't know how the Linux one differs but if it can crash the program and
> not show a sign of error then something could be wrong with POV itself.
> But maybe it's sort of looping on some calculation.
> --
> Farewell,
> Bob

I shall take this moment to appologize for the attachment of the file.  It 
really occured to me that should have been done in binaries.  I posted to 
the advance-users group first and then realized after the face that I would 
get a wider responce from this newsgroup.  With that being said I will 
clearify my situation.  I am a physics major in Missouri and want to be 
able to make really cool 3d animations of my class homework, just for fun 
really.  I thought that maybe I could have a math program output a file for 
each time step and then include that list of points in a povray file.  I 
was unable to find a whole lot of information on that.  So I get 3.5 since 
it said that it had partial sums in the list of available functions.  When 
I use small functions like just sin(x) or sin(x)*(x^3) or something like 
that it works fine.  When I have the function as is listed in the attached 
file the program just stops.  Window pops up and it just sits there.  The 
following is the output of the program.

---SNIP

Persistence of Vision(tm) Ray Tracer Version 3.5 Unix (.Linux.gcc)
  This is an official version prepared by the POV-Ray Team. See the
   documentation on how to contact the authors or visit us on the
   internet at http://www.povray.org/.
Copyright 1991-2002 POV-Ray Team(tm)
Parsing Options
  Input file: ./isosurfaces.pov (compatible to version 3.5)
  Remove bounds........On  Split unions........Off
  Library paths: /usr/local/lib/povray-3.5
    /usr/local/lib/povray-3.5/include /usr/local/share/povray-3.5
    /usr/local/share/povray-3.5/include
Output Options
  Image resolution 320 by 240 (rows 1 to 240, columns 1 to 320).
Warning:   Rendering to screen only. No file output.

  Graphic display......On  (type: 0, palette: 3, gamma:  2.2)
  Mosaic preview......Off
  CPU usage histogram.Off
  Continued trace.....Off  Allow interruption..Off  Pause when done......On
  Verbose messages.....On
Tracing Options
  Quality:  3
  Bounding boxes.......On  Bounding threshold: 3
  Light Buffer.........On  Vista Buffer.........On  Draw Vista Buffer...Off
  Antialiasing........Off
Animation Options
  Clock value....   0.000  (Animation off)
Redirecting Options
  All Streams to console.........Off
  Debug Stream to console.........On
  Fatal Stream to console.........On
  Render Stream to console........On
  Statistics Stream to console....On
  Warning Stream to console.......On


Parsing......File: ./isosurfaces.pov  Line: 69
Warning: Itteration

.

Creating bounding slabs.
Scene contains 6 frame level objects; 2 infinite.

Creating vista buffer.
Displaying...
Using 16 bit TrueColor visual...
  -:--:-- Rendering line    1 of  240. Warning: Camera is inside a 
non-hollow object. Fog and participating media
may not work as expected.

---SNIP

I let it run all night and got nothing, not a single line.  Could this be a 
bug in povray 3.5?  If I take the sum out and put like sin(x) it works fine 
and fast.  Like I said before, sorry about the bad posing style but lets 
try thig again.

Justace

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Sorry, I hadn't noticed there was a file attached since they aren't expected
in this group.

I don't know the sum() function but I got it to render by using sum(n,
0, -1, -1*((40/(n*pi))), reasoning that it wasn't able to deal with the
positive value and the negative equation together. Like I said though, I
just don't know this function. It does seem to be rendering when left
unchanged, POV was telling me it was doing 220PPH 3 minutes into it and was
steadily decreasing in speed. Anyway, it isn't the Linux version causing a
problem.

Maybe this discussion needs to get back to the advanced group, but please
cancel both your original posts if you can; and like Thorsten, said put the
scene file text into the message body.

--
Farewell,
Bob

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"Justace Clutter" <pro### [at] corpranetnet> wrote in message
news:3db62bce@news.povray.org...
[snip]
> do anyhing and I have to kill it with a sig 9 to get it to exit.  I
use

Well, I don't understand your function :} but tried your pov file (I
added hollow to planes to kill warning).

After 5 mins I had 30+ pixels rendered at 320*240 (they appeared when
I hit stop) but I could not stop the render although the pause button
worked. I had to exit pov to stop the render.

I'm using 3.5.icl.win32 and Win98SE with 160MB ram.

Alf

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On Wed, 23 Oct 2002 14:56:57 -0400, Alf Peake quoth:

> "Justace Clutter" <pro### [at] corpranetnet> wrote in message
> news:3db62bce@news.povray.org...
> [snip]
>> do anyhing and I have to kill it with a sig 9 to get it to exit.  I
> use
> 
> Well, I don't understand your function :} but tried your pov file (I
> added hollow to planes to kill warning).
> 
> After 5 mins I had 30+ pixels rendered at 320*240 (they appeared when I
> hit stop) but I could not stop the render although the pause button
> worked. I had to exit pov to stop the render.

It sounds like it's just an extremely slow render.  At a resolution of
2x2, the render completed in under a second.  At 3x3, it was still
rendering the second pixel after 70 minutes.

-- 
Mark

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Wasn't it Justace Clutter who wrote:
>I am trying to get render a frame with a wave function built in it.  The 
>function is the specific solution after seperation of variables was done.  
>Anyway all that is irrelelvant.  When I try to render the frame it just 
>sits there and does nothing.  the povray process accums time but does not 
>do anyhing and I have to kill it with a sig 9 to get it to exit.  I use 
>Linux if you have not already guessed.  Any information on this would be 
>wonderfull.
>

A fairly minimal piece of code that exhibits the problem is

// This is the entire scene file
#declare F = function {sum(n, 1, 1, 1*(2/(n*1)))}
#debug str(F(0,0,0),5,5)
// -----------------------------

Any attempt to simplify the expression causes the scene to complete, but
does not always return what I consider the right answer.


Consider these:-

  #declare F = function {sum(n, 1, 1, n)}

evaluates to 1.00000, which I reckon is OK, but

  #declare F = function {sum(n, 1, 1, 1*n)}

evaluates to 2.00000, which I reckon is wrong.


  #declare F = function {sum(n, 3.1234, 4.1234, 1)}   => 2.00000 : OK
  #declare F = function {sum(n, 3.1234, 4.1234, 1*1)} => 5.12340
           which is wrong by an amount equal to the initial value of n.

  #declare F = function {prod(n, 1,2, n)}     =>  2.00000 : OK
  #declare F = function {prod(n, 1,2, 1*n)}   =>  4.00000 : wrong
  #declare F = function {prod(n, 1,2, n/1)}   =>  4.00000 : wrong
  #declare F = function {prod(n, 1,2, (n+0))} =>  4.00000 : wrong

-- 
Mike Williams
Gentleman of Leisure

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Mike Williams wrote:

> Wasn't it Justace Clutter who wrote:
>>I am trying to get render a frame with a wave function built in it.  The
>>function is the specific solution after seperation of variables was done.
>>Anyway all that is irrelelvant.  When I try to render the frame it just
>>sits there and does nothing.  the povray process accums time but does not
>>do anyhing and I have to kill it with a sig 9 to get it to exit.  I use
>>Linux if you have not already guessed.  Any information on this would be
>>wonderfull.
>>
> 
> A fairly minimal piece of code that exhibits the problem is
> 
> // This is the entire scene file
> #declare F = function {sum(n, 1, 1, 1*(2/(n*1)))}
> #debug str(F(0,0,0),5,5)
> // -----------------------------
> 
> Any attempt to simplify the expression causes the scene to complete, but
> does not always return what I consider the right answer.
> 
> 
> Consider these:-
> 
>   #declare F = function {sum(n, 1, 1, n)}
> 
> evaluates to 1.00000, which I reckon is OK, but
> 
>   #declare F = function {sum(n, 1, 1, 1*n)}
> 
> evaluates to 2.00000, which I reckon is wrong.
> 
> 
>   #declare F = function {sum(n, 3.1234, 4.1234, 1)}   => 2.00000 : OK
>   #declare F = function {sum(n, 3.1234, 4.1234, 1*1)} => 5.12340
>            which is wrong by an amount equal to the initial value of n.
> 
>   #declare F = function {prod(n, 1,2, n)}     =>  2.00000 : OK
>   #declare F = function {prod(n, 1,2, 1*n)}   =>  4.00000 : wrong
>   #declare F = function {prod(n, 1,2, n/1)}   =>  4.00000 : wrong
>   #declare F = function {prod(n, 1,2, (n+0))} =>  4.00000 : wrong
> 

So we learn from this that the sum function is just not to be trusted here.
I guess that I shall be needing to use something else.
I thought that I could have gnuplot plot the function output to a table and 
then post-process the table.  There the values would be given as point 
triples.  Then to pull those into povray somehow.  I looked into this and 
it looked as though the bicubic patch would work but then no and then I 
thought about the mesh or mesh2 object.  I just do not have experiance with 
this, what object is reccommemded for this kind of work.  I have searched 
the internet for examples of people doing scientific plotting with povray 
in this capcity and did not come up with much of anything.

I guess that I would list the sum and prod functions as buggy, I will submit 
a bug report to the pov gods.  Thanks for thinking to do that.

Justace

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Wasn't it Justace Clutter who wrote:

>So we learn from this that the sum function is just not to be trusted here.
>I guess that I shall be needing to use something else.

You could always perform the summation in POV code, rather than using
sum(). Like this:-

  function {
      z
      #declare n=1;
      #while (n<50)      
        +((40/(n*pi)))*(cos(n*pi)-cos((n*pi)/2))*sin((n*pi*x)/10)
                          *exp(-1*(((pow(n,2)*pow(pi,2))/100)*0))
        #declare n=n+1;  
      #end
  }
  max_gradient 86



-- 
Mike Williams
Gentleman of Leisure

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