Hiya,

I'm really new to MegaPOV, and I have some trouble understanding how to get
the mechism thingie to work as I want it to ;-)

For example, using the cloth.pov sample, is there a way to generate the
final image (or an arbitrary frame) without having to render all previous
images between the first and the last?

I've tried by tweaking the step_count and time_step parameters (and to be
honest I find it hard to figure out exactly what they do), tried by setting
up the .ini so only 2 frames are generated, but still no luck.

Is there a way to let the mechism do its simulation/iteration/whatever in a
single render only? Ive noticed that tweaking the step_count / time_step
doesn't affect much when Im not animating (but then, as mentioned, I havent
really grasped what to expect from them)...

Any help/tips is appreciated.

Thanks

/Per

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"PerFnurt" <per### [at] hotmailcom> wrote:
> Hiya,
>
> I'm really new to MegaPOV, and I have some trouble understanding how to get
> the mechism thingie to work as I want it to ;-)
>
> For example, using the cloth.pov sample, is there a way to generate the
> final image (or an arbitrary frame) without having to render all previous
> images between the first and the last?

if you have the saved simulation data: (*.dat)
render a still image(no animation) using this:
global_settings {
  mechsim {
    step_count 0 // disable simultion
    collision { off }
    topology {
      load_file "your_final_simulation_data.dat"
    }
  }
}

to simulate all the way to the final image, and then render the result:
set time_step as usual, and multiply step_count by the frame number you
want.
(step_count = the number of simulation steap between rendered frames.)
do the above while rendering a single frame animation.
(note: simulation will still take as long as simulating all separate frames
did before, it only saves the rendering time)

disadvantage:
-at least the windows GUI version has trouble stopping the simulation (can
 only be interrupted during actual rendering, witch you do after a long
time)
-no way to check if things are simulating as expected.

what i do:
render with really low resolution and no aa and cancel the animation at the
point i thing it has simulated what i need.
(you can rename the .dat file, to prevent overwriting it by accident)

then make a slightly changed pov file, (as above) to render the result in
hi-res, with radiosity/HDR, nice textures, etc.

(i also experimented with replacing simulated objects with pov objects)
http://jwstolk.afreehost.net/image.htm

hope this helps.
jaap.

Post a reply to this message

PerFnurt wrote:
> Hiya,
> 
> I'm really new to MegaPOV, and I have some trouble understanding how to get
> the mechism thingie to work as I want it to ;-)
> 
> For example, using the cloth.pov sample, is there a way to generate the
> final image (or an arbitrary frame) without having to render all previous
> images between the first and the last?

As Jaap said you can generate the final image without *rendering* every 
frame but not without simulating the whole time (this is nothing 
specific to MegaPOV, it is inherent to any simulation like this).  So 
you could do something like:

#if (clock_on)
   ...
   (insert the old simulation timing here)
#else
   step_count Frame_Count*Steps
   time_step ...
   ...
#end

where 'Steps' is the old number of steps per frame and Frame_Count the 
number of frames you want to simulate.

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 27 Feb. 2005 _____./\/^>_*_<^\/\.______

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