Record a video with Freefem++ plot

Hello everyone
I would like to know if there is a way to edit a video from images like freefem++ does when we display the solution of an evolution equation at each moment. For example I solve a heat equation and with plot I display the solution u(x,y) at each time t. I would like to know if there is a way to record the images directly and how I can read them simultaneously one after the other.

Thank you for helping me.

You should use ParaView for that.

How to store with savevtk u(t,x,y) in block to be able to read it with paraview. that is to say store u at each time t but in the same .VTU file

See, e.g., FreeFem-sources/examples/hpddm/laplace-adapt-3d-PETSc.edp at 220957ed86797a6c1ed771f1fe1c27078e94f28a · FreeFem/FreeFem-sources · GitHub.

I did not find a solution within FreeFEM, I did something like that by:

  • transferring to python with pyfreefem (does not work on windows)
  • displaying with matplotlib while storing in an image buffer
  • using opencv to generate a video from the images
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I did not find a solution within FreeFEM

There is one, and I just gave a link above. It’s also explained here (it works the same whether you are using things in parallel or not).


Thank you very much for your answers.

AFAICT, there are a lot of ways to make movies with a series of slides but if you want to watch
in real time, the FF plots are ok but limited and specific to FF. I’ve finally gotten around
to making something I call mjmdatascope which is designed mostly to monitor
progress from a variety of sources ( interfaces now for FF,R, and c++ code )
and save images or movies. Right now I just have 1D FF but eventually will
add more stuff. If you can’t find a solution you could look at this and make suggestions
for priorities. I’ve got a couple examples up there including a recent movie of 2D
sim that is jerky but fixing that :slight_smile:

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It’s very interesting. Thank you very much and happy new year.