Hi Ryan, When I look at these movies carefully, it looks like they are using streaklines that are seeded for a short burst. It looks like they pick a number of seeds each time step and start a streakline from each and keep them active for a few time steps. Then those streaklines seem to be killed eventually. It also appears as if they are playing with transparency depending on the age of the streakline. Am I right?
-berk On Tue, Jan 14, 2014 at 2:20 PM, Ryan Abernathey <ryan.abernat...@gmail.com> wrote: > Hello, > > I am continuing my ongoing quest to do something like this > http://earth.nullschool.net/#current/wind/isobaric/1000hPa/orthographic=267.73,5.54,350 > or this > http://www.youtube.com/watch?v=xusdWPuWAoU > in Paraview using ***time dependent velocity vectors***. > > While the LIC plugin is very cool, it does something different. I followed > the previous suggestion and tried to use the streamline filter: > http://paraview.org/Wiki/ParaView/Custom_Filters > Unfortunately that is not quite right either. > > The problem with the streamline filter is that it treats each timestep as > completely independent and regenerates the streamlines whenever the velocity > field changes. (This is the correct behavior: streamlines are defined by the > *instantaneous* flow.) > > What we see in those videos are truly particle trajectories. In particular: > - particles are seeded randomly (in space and time) > - they leave a decaying trail (sometimes called a streaklet) > - the particles disappear after a short lifetime > This is the combination of ingredients I need to reproduce in paraview. > > The best candidate is clearly the ParticleTracer filter. However, I have hit > a serious problem: it doesn't appear that this filter is able to make the > particles "die" after a temporal lifetime. Compare the v 3.3 documentation > http://paraview.org/OnlineHelpCurrent/ParticleTracer.html > with the current documentation > http://paraview.org/Wiki/ParaView/Users_Guide/List_of_filters#ParticleTracer > In the old version, there was an option called "Termination Time" that is > missing from the new version. > > Without such an option, the particles will never disappear, the domain will > get more and more crowded, and the computational expense will grow with > time. > > Let me know if you have any suggestions or if you know how to re-enable this > Termination Time option. > > Thanks a lot, > Ryan > > _______________________________________________ > Powered by www.kitware.com > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Please keep messages on-topic and check the ParaView Wiki at: > http://paraview.org/Wiki/ParaView > > Follow this link to subscribe/unsubscribe: > http://www.paraview.org/mailman/listinfo/paraview > _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the ParaView Wiki at: http://paraview.org/Wiki/ParaView Follow this link to subscribe/unsubscribe: http://www.paraview.org/mailman/listinfo/paraview