Making Animation
 

Hi FOAMers
I run dam break tutorial of OpenFOAM. How could I make an animation for surface of fluid in time with paraview?
Any help will be appreciated.
All the best

Hi

Create a contour which is based on gamma and set the value to 0.99 or 0.01 depending on gamma = 1 water or gamma = 0 water.

Hope this helps.

Making Animation
 

Hi,
First you create contours for say 20 time steps. Then use ImageMagick package to convert the jpeg to mpeg.

you ref to page U-165 of UserGuide

Hi mecbe
Thank you very much.
Best regards

Hi

You could also build paraview with ffmpeg support and be able to export directly to avi.

you need the right version of ffmpeg from here

Hi linnemann
thank you very much but I don not understand your guid. Is it for windows OS?
and
when I run dam break tutorial an try to convert jpg files according to users guide pdf file I got this error:
execvp failed, errno = 2 (No such file or directory)
convert: "mpeg2encode" "/tmp/gmL2nNc9" "movie.mpg".
convert: Delegate failed ("mpeg2encode" "%i" "%o").
Could any one help me?
Thanks

Hi

I would suggest that you use ffmpeg, not necessarily as a build in functionality in paraFoam. My experience is that ffmpeg is faster and uses less memory than older versions of convert (newer versions rely on ffmpeg).

One comment on ffmpeg, be sure to use the "-b Nk" option, with N being large, e.g. 20000, as it specifies the maximum bit rate, and the default is so low that it results in movies of an awful quality.

Best regards,

Niels

Making Animation
 

Hi Niels Gjoel Jacobsen
Thank you very much for your reply. I have two problems.
1. According to read me file of ffmpeg when I type
in terminal I got this error:
2. Always I want to build paraview from its source it does not work correctly. So I install paraview via synaptic package manager but in red me file has been written:
7) Finally rebuild VTK or ParaView.
Is it possible for me not to rebuild paraview?
Could you or any one help me?
Thanks
Best regards

Hi
what do mean "Frame rate(fps)" and "No.Of Frames/timestep" in CFD cases?
there is frame rate (-r option) in ffmpeg too,whats difference between this option and frameRate that is specified in paraview for making images?
which values is better and why?

Greetings to all!

@Ehsan
So, let me try to explain this in a simple way:

1. A frame in movies is a single picture (or image).
2. FPS means "Frames Per Second".
3. Frames per Timestep depends the type of simulation you're performing (steady-state vs transient), but in transient this equates to the following example:
   1. You have a simulation that has 2.0 seconds of real time simulation (which probably took several hours to simulate).
   2. You chose to only save every 0.1s of real time - this is the referred time step.
   3. This means that you have 21 frames with unique data, which includes the 0s time step.
4. As for the best value, the paradigm is simple: how fast do you want people to see your simulation?
   • If you want the simulation to be shown in real time, you only need 10 frames per second, because you only have 10 frames of unique data to represent.
   • If you want people to see the simulation more slowly than real time, for example to show 2.0s displayed in 10.0s, then this means that you want 1/5 th of the frame rate, namely 2 frames per second (10 real fps * 1/5 = 2).

I hope this makes things a lot clearer.

Best regards,
Bruno