Editing MovieSchool 5 (section)

===Representations===

Scenes are the only way to change representations (eg sticks to cartoon).  In PyMOL to show representation changes we need to have a list of scenes, that we then assign to a given frame.  Once this is done we can reinterpolate through scenes to have beautifully smooth transitions.

PyMOL makes it very easy to setup your scenes--for that ''look''--and save them in a stack (and, now, even move them around).  We covered scenes already in the tutorial, so please check that if you need more help on scenes, or see [[:Category:Scenes]] for more commands and hints.

In PyMOL, to attach a scene to a frame (or, technically a frame to a scene) we simply do the following:
<source lang="python">
mview store, scene=sceneName
</source>

Let's take a look at a simple movie that changes the representation of some object.  This will show a tryptophan going from lines to sticks and back.
<source lang="python" line=1>
set scene_buttons, 1
set movie_panel, 1

# make a 90 frame movie, all STATE 1.
mset 1 x90

# load a trypotphan fragment
frag trp

# Tell PyMOL to call this current view '001'.
scene 001, store
# goto frame 1 and store this scene & camera
frame 1
mview store, scene=001

# setup the next 'view'
as sticks
scene 002, store

# goto frame 60 and show sticks
frame 45
mview store, scene=002

mview reinterpolate
mplay
</source>

To show you how easy adding camera motions + representations is, simply insert after line 17 (''as sticks'') a new line 18 that only has
<source lang="python">
orient
</source>

Here's what's happening in the movie, above.  Lines 1&mdash;2 set PyMOL up to show you [[scene_buttons|scene buttons]] and the [[Movie_panel|movie panel]].  Line 5 makes a 90 '''frame''' movie that only spans the first state.  Line 8 makes the TRP fragment from PyMOL's stored knowledge of residues.  Line 11 asks PyMOL to store this current 'view' as a [[scene]] and call that scene ''001''.  Now that a scene is made, we need to associate with a frame.  So, we goto frame 1 in line 13.  In line 14 we actually make the scene-to-frame assignment with the [[mview]] store command, specifying the mapping between scene 001 and frame 1.  Lines 17 and 18 change the representation from lines to sticks and then orients the TRP residue (which causes the camera to move).  In line 19, we save this new camera position and the sticks representation of TRP in the scene called ''002''.  Next, in line 22, we go somewhere ahead in the movie, here 1/2 way to the end.  Line 23 assigns scene ''002'' to frame 45.  Lastly, because we changed the camera position, we need to reniterpolate it's movement, and that's done in line 24.  As you know [[mplay]] just plays the movie.

* '''Hint''': Clear frames with '''mview clear'''
* '''Hint''': Clear scenes with '''scene sceneName, delete'''; you can delete all scenes with '''scene *, delete'''.


Now that we have that, let's learn more complex tricks with motion and representations!