On Sun, 12 Oct 2008, Paul M. Grant wrote: paul,
PG> Axel, thanks for getting back on this. Let me think about your suggestion PG> and see what others have to comment as well. it is actually quite difficult to give a recommendation, since everybody uses a different nomenclature when it comes to visualization and animations, based on background, software being used and ability to put visual ideas in words (which i always found very difficult). PG> Reflecting on "animation" in general a little more, I wonder if there's a PG> Linux screen capture tool available somewhere analogous to KDE Ksnapshot for PG> jpeg images, but which could capture motion in addition resulting in an mpeg PG> file. Now that would be a handy and nifty gadget for lots of purposes! there is a number of ways to do this and it depends on whether you want a "realtime" capture or just "one frame per update" type animations. the former could in principle be done on any x11 based machine with some smart shell scripting using the xwd utility after figuring out the x window id of the display window. the latter is a method that is been used by many "movie maker" tools that are integrated into visualization programs. in both cases you assemble a sequence of snapshots and then use tools like ppmtompeg, mencoder, convert, gifsicle and so on to turn them into an mpeg, avi, or animated gif movie. please note that "realtime" capture (for mpeg) would require a screenshot frequency of up to 30 snapshots per second which is probably beyond the capability of most hardware, not to mention the limitations of the X protocol... but then again, it would reduced the load and hardware requirements at playback time a lot. it should be possible to write a proof-of-concept code based on existing tools rather quickly. i'll put it on my (ever growing) TODO list and will get back to you if i have something that is worth trying out. cheers, axel. PG> PG> Paul M. Grant, PhD PG> Principal, W2AGZ Technologies PG> Visiting Scholar, Applied Physics, Stanford (2005-2008) PG> EPRI Science Fellow (Retired) PG> IBM Research Staff Member Emeritus PG> w2agz at pacbell.net PG> http://www.w2agz.com PG> ? PG> ? PG> PG> PG> -----Original Message----- PG> From: pw_forum-bounces at pwscf.org [mailto:pw_forum-bounces at pwscf.org] On PG> Behalf Of Axel Kohlmeyer PG> Sent: Sunday, October 12, 2008 5:18 PM PG> To: Paul M. Grant PG> Cc: 'PWSCF Forum' PG> Subject: Re: [Pw_forum] On making a *.axsf file with XCrySDen PG> PG> On Sun, 12 Oct 2008, Paul M. Grant wrote: PG> PG> hi paul, PG> PG> not sure whether this is helpful, but i managed to do something PG> similar to what you describe with VMD (granted VMD is still missing PG> a lot of features for crystals etc. so it may not work as well for you). PG> PG> the problem is that usually volumetric data sets are not associated PG> with the individual time step of an animation. the VMD script works PG> because it is loading a sequence of cube files with a 1:1 correlation PG> of coordinate and volumetric data and then makes the correlation by PG> replacing the volumetric data sets through a callback hook to the PG> animation loop frame number variable (standard tcl method). see: PG> PG> http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/cpmd-vmd/part5.html#c PG> hap7_sect6 PG> PG> for more complicated scenarios (e.g. i have dome some nice movies of PG> the fluctuations of spin densities of electron pairs in the cavities PG> of an electride-like compound) one has to write more complicated tcl PG> scripts. PG> PG> i would assume that there may be similar scripts possible with xcrysden, PG> provided the script API is flexible enough... (never tried it). PG> PG> cheers, PG> axel. PG> PG> PG> PG> How does one make an animated axsf file using XCrySDen directly? For PG> PG> example, suppose I want save in an axsf file the animation of an PG> isosurface PG> PG> of charge density moving through a given unit cell. I can save the PG> PG> "situation" as an .xcrysden script file for play back, but on loading it PG> PG> doesn't raise the Modify -> Animation Controls option. Only an .axsf PG> file PG> PG> apparently does this. Do I have to go through the script file inserting PG> PG> "ANIMSTEPS" by hand? PG> PG> PG> PG> I note that the XCrySDen forum archives has had no entries since PG> April.Is PG> PG> PW_Forum now the appropriate target for XCrySDen issues? PG> PG> PG> PG> Paul M. Grant, PhD PG> PG> Principal, W2AGZ Technologies PG> PG> Visiting Scholar, Applied Physics, Stanford (2005-2008) PG> PG> EPRI Science Fellow (Retired) PG> PG> IBM Research Staff Member Emeritus PG> PG> w2agz at pacbell.net PG> PG> http://www.w2agz.com <http://www.w2agz.com/> PG> PG> PG> PG> PG> PG> PG> PG> PG> PG> PG> PG> -- ======================================================================= Axel Kohlmeyer akohlmey at cmm.chem.upenn.edu http://www.cmm.upenn.edu Center for Molecular Modeling -- University of Pennsylvania Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323 tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel: 1-215-898-5425 ======================================================================= If you make something idiot-proof, the universe creates a better idiot.
