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18 May 2024 22:30:16 EDT (-0400)
  Clothsim problem (Message 1 to 9 of 9)  
From: Gail Shaw
Subject: Clothsim problem
Date: 11 Apr 2001 07:53:15
Message: <3ad445ab@news.povray.org>
I downloaded clothsim version 0.4.0 and I'm trying to
create a banner waving in the wind. I've tried with
simulation steps 5000,10000 and 20000 but everytime
I get a message saying that 1.04625e+301 (or some similarly
large number) is not finite. followed by

      0 [main] CLOTH 244807 handle_exceptions: Exception:
STATUS_ACCESS_VIOLATIO
N
    867 [main] CLOTH 244807 stackdump: Dumping stack trace to
CLOTH.EXE.stackdum
p

my input file was as follows

global_settings {
 step 0.25
 wind <0,-0.3,0>
}

cloth {
 x_size 50
 y_size 50
 dist 2/50
 stiffness 0.1
 weight 0.5
 position {<0,0,1>,<1,0,1>,<1,0,0>}
 attach {0,0,<0,0,0.17>}
 attach {1,0,<1,0,-0.17>}
}


Am I doing something wrong? I assume there's something
about the above input that the simulator doesn't like as I can run
the flag and sample files. I've tried on both a P3 450 and a P2 300
both with 128 MB ram.

Any help will be greatly appreciated.

Gail
*************************************************************************
* gsh### [at] monotixcoza                *   Step into the abyss,           *
* http://www.rucus.ru.ac.za/~gail/   *   and let go.        Babylon 5   *
*************************************************************************
* The difficult we do immediately, the impossible takes a little longer *
*************************************************************************


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From: Gail Shaw
Subject: Re: Clothsim problem Addendum, OS info
Date: 11 Apr 2001 08:03:44
Message: <3ad44820@news.povray.org>
the p3 450 is running Win95 OEM2 and the p2 300 is
running win98

Gail
--
*************************************************************************
* gsh### [at] monotixcoza                *   Step into the abyss,           *
* http://www.rucus.ru.ac.za/~gail/   *   and let go.        Babylon 5   *
*************************************************************************
* The difficult we do immediately, the impossible takes a little longer *
*************************************************************************


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From: Francois Labreque
Subject: Re: Clothsim problem
Date: 11 Apr 2001 08:24:45
Message: <3AD44BEA.4BEDED5C@videotron.ca>
Gail Shaw wrote:
> 
> I downloaded clothsim version 0.4.0 and I'm trying to
> create a banner waving in the wind.

Same here.

> I've tried with simulation steps 5000,10000 and 20000 but
> everytime I get a message saying that 1.04625e+301 (or some 
> similarly large number) is not finite. followed by

Same here.

> my input file was as follows
> 
> global_settings {
>  step 0.25
>  wind <0,-0.3,0>
> }
> 
> cloth {
>  x_size 50
>  y_size 50
>  dist 2/50
>  stiffness 0.1
>  weight 0.5
>  position {<0,0,1>,<1,0,1>,<1,0,0>}
>  attach {0,0,<0,0,0.17>}
>  attach {1,0,<1,0,-0.17>}
> }

Argh!!  Same here too!!! (except the z component)

> 
> Am I doing something wrong? I assume there's something
> about the above input that the simulator doesn't like as I can run
> the flag and sample files.

Reduce the step to 0.1 or something similar.  That solved it for me,
although it takes 200 000 iterations before my flag looks like it has
moved a bit.

And if you haven't read my earlier post on the subject, be warned that
there's a typo in the strenght [sic] keyword.
-- 
Francois Labreque | It is by caffeine alone I set my mind in motion, it
    flabreque     | is by the beans of Java that thoughts acquire speed,
        @         | the hands acquire shaking, the shaking becomes a 
   videotron.ca   | warning, it is by caffeine alone I set my mind in
                  | motion.
                               - Stolen from Badger's .sig file


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From: Gail Shaw
Subject: Re: Clothsim problem
Date: 11 Apr 2001 09:02:54
Message: <3ad455fe@news.povray.org>
Francois Labreque <fla### [at] videotronca> wrote in message
news:3AD44BEA.4BEDED5C@videotron.ca...
>
>
> Reduce the step to 0.1 or something similar.  That solved it for me,
> although it takes 200 000 iterations before my flag looks like it has
> moved a bit.

I've tried 0.1, 0.2 and 0.25 all with the same problem. Will try smaller
tonight

> And if you haven't read my earlier post on the subject, be warned that
> there's a typo in the strenght [sic] keyword.

I did read it but forgot. That explains why the sample wouldn't work.

Thanks

Gail
--
*************************************************************************
* gsh### [at] monotixcoza                *   Step into the abyss,           *
* http://www.rucus.ru.ac.za/~gail/   *   and let go.        Babylon 5   *
*************************************************************************
* The difficult we do immediately, the impossible takes a little longer *
*************************************************************************


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From: Andy Cocker
Subject: Re: Clothsim problem
Date: 11 Apr 2001 14:47:14
Message: <3ad4a6b2@news.povray.org>
"Gail Shaw" <gsh### [at] monotixcoza> wrote in message
news:3ad445ab@news.povray.org...
> I downloaded clothsim version 0.4.0 and I'm trying to
> create a banner waving in the wind. I've tried with
> simulation steps 5000,10000 and 20000 but everytime

You shouldn't need anything like this number of steps.

> I get a message saying that 1.04625e+301 (or some similarly
> large number) is not finite. followed by
>
>       0 [main] CLOTH 244807 handle_exceptions: Exception:
> STATUS_ACCESS_VIOLATIO
> N
>     867 [main] CLOTH 244807 stackdump: Dumping stack trace to
> CLOTH.EXE.stackdum
> p

I believe this is mainly down to the fact that you are creating such a small
piece of cloth ( dist 2/50 ), and the way it interacts with stiffness etc. I
think you'd be better off creating a large flag ( e.g dist 1 ), and scaling
it smaller. Also, a value of 50 for the x and y is way over the top. You
could get away with 20, but 25 would be better. This will also help with the
parse time.

>
> my input file was as follows
>
> global_settings {
>  step 0.25
>  wind <0,-0.3,0>
> }
>
> cloth {
>  x_size 50
>  y_size 50
>  dist 2/50
>  stiffness 0.1
>  weight 0.5
>  position {<0,0,1>,<1,0,1>,<1,0,0>}
>  attach {0,0,<0,0,0.17>}
>  attach {1,0,<1,0,-0.17>}
> }

I'm unsure as to what you're trying to achieve.. I did a test render (having
scaled up the cloth), and it looked like your attatch points are at the
lower corners of the flag/banner... so the cloth would have to fall a long
way AND back on itself to be where it should be with regard to the wind (I
think... attatch points and position still cause me great headaches :-) )

If you tell me the coordinates of where the flag should be in your scene,
I'd be happy to send you a *.cl file.

All the best,

Andy


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From: Andy Cocker
Subject: Re: Clothsim problem
Date: 11 Apr 2001 14:47:16
Message: <3ad4a6b4$1@news.povray.org>
"Francois Labreque" <fla### [at] videotronca> wrote in message
news:3AD44BEA.4BEDED5C@videotron.ca...
>
>
> Gail Shaw wrote:
> >
> > I downloaded clothsim version 0.4.0 and I'm trying to
> > create a banner waving in the wind.
>
> Same here.

Did you know that in the source code there is example code of a flag
animation?


> Reduce the step to 0.1 or something similar.  That solved it for me,
> although it takes 200 000 iterations before my flag looks like it has
> moved a bit.

You should be able to use just 25 steps between each frame.. nothing like
200 000. See the example file above. It uses -s 25 between frames.

Andy


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From: Gail Shaw
Subject: Re: Clothsim problem
Date: 12 Apr 2001 01:52:34
Message: <3ad542a2@news.povray.org>
Andy Cocker <big### [at] mariner9fsnetcouk> wrote in message
news:3ad4a6b2@news.povray.org...
>
>
> I'm unsure as to what you're trying to achieve.. I did a test render
(having
> scaled up the cloth), and it looked like your attatch points are at the
> lower corners of the flag/banner... so the cloth would have to fall a long
> way AND back on itself to be where it should be with regard to the wind (I
> think... attatch points and position still cause me great headaches :-) )

I was getting very confused with the coord system.
(x positive to the right, y positive into scene, z positive up. Is that
correct?)
I'm used to the left handed system

> If you tell me the coordinates of where the flag should be in your scene,
> I'd be happy to send you a *.cl file.
>

I was trying for a banner attached to a pole top left and right (one side
slightly
lower than the other)

Thanks for all the suggestions. I'll have another try with it tonight.

Gail
*************************************************************************
* gsh### [at] monotixcoza                *   Step into the abyss,           *
* http://www.rucus.ru.ac.za/~gail/   *   and let go.        Babylon 5   *
*************************************************************************
* The difficult we do immediately, the impossible takes a little longer *
*************************************************************************


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From: Andy Cocker
Subject: Re: Clothsim problem
Date: 12 Apr 2001 13:04:23
Message: <3ad5e017@news.povray.org>
"Gail Shaw" <gsh### [at] monotixcoza> wrote in message
news:3ad542a2@news.povray.org...
> I was getting very confused with the coord system.
> (x positive to the right, y positive into scene, z positive up. Is that
> correct?)

That's correct.

> I'm used to the left handed system

Me too.

> Thanks for all the suggestions. I'll have another try with it tonight.

You're welcome.

Andy


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From: Gail Shaw
Subject: Re: Clothsim problem
Date: 18 Apr 2001 06:23:50
Message: <3add6b36@news.povray.org>
All is now working. It helps if the position vectors are
sensible which

>  position {<0,0,1>,<1,0,1>,<1,0,0>}

is not

Thanks to everyone who gave suggestions.

Gail
*************************************************************************
* gsh### [at] monotixcoza                *   Step into the abyss,           *
* http://www.rucus.ru.ac.za/~gail/   *   and let go.        Babylon 5   *
*************************************************************************
* The difficult we do immediately, the impossible takes a little longer *
*************************************************************************


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