> First up: Is there any way to tell PyMol *not* to change its view when > loading a > PDB file
set auto_zoom,0 > Secondly: Below is an example of a small hack I have written when making > one > particular movie. This one overlays two molecules related by a 2-fold > axis by > doing a simple rotation. > > > def overlay_chains(write_frames=0, ray=0): > > # Now interpolate each point in the matrix > > i = 1 > > n = 45 > > while i <= n: > > # This is the only code I would imagine I should need: > > # cmd.mdo( "%d" % (i), "rotate y,2,chain_a; rotate y,-2,chain_b" ) > > # In the end I used the following cludge: > > cmd.do( "rotate y,2,chain_a" ) > > cmd.do( "rotate y,-2,chain_b" ) > > if ( ray ): > > cmd.do( "ray" ) > > if ( write_frames ): > > cmd.do( "png overlay_frames/overlay_%03d.png" % (i) ) > > i = i+1 > > cmd.extend( "overlay_chains", overlay_chains ) > > What is wrong with the cmd.mdo line above? The functionality I would > expect > would be that in each frame of the movie both chains are rotated 2 deg (in > the > relevant directions). What I get is that the change only occurs once per > loop > of the movie. That is to say that if I set up a movie using 'mset 1 -45' > the positions only get updated once per 45 frames, not once per frame > (which is > what I would have expected). Do you have 45 states, or just one? If you have just one, did you use the "mset 1 x45" statement to create 45 frames consisting of that one state? And finally, are you using mpng to write the movie? > Thridly: Is there any command to tell PyMol to play a movie ONLY ONCE. > This > would be *really* useful if it has not yet been implemented. I just added a "movie_loop" setting for you. Look for it in the next version. > Fourth (and last): Is there a difference b/w the ray-tracing used by the > standard 'ray' command and the 'mpng' command? I have noticed that if I > take a > still of a molecule, and then render the molecule rotating (for example) > all > within the one script I observe real differences b/w what should be > identical > frames. The clipping planes and the z camera distance move considerable. > I can > post code if that would help. Ray simply passes the current scene to the ray tracer. Mpng runs through the movie from the beginning and applies any mmatrix, mdo, or mappend operations you may have defined for the movie before handing each scene off to "ray". (Note that movie.rock and movie.roll use mdo) What you describe sounds more like the difference between having a perspective view in OpenGL and orthoscopic in the rendered scene, but that difference should occur with both ray and mpng. Cheers, Warren
