Editing Vtk/MovieMaking

=Making a Movie=
Here are steps that can be followed to construct an animated gif (movie) from a set of images that have been constructed using VisTrails or MicroSoft's Excel.


{{LSU_HBook_header}}

==Generate a Sequence of (PNG) Images==

===Inside VisTrails===
<!-- [[Image:LSUtest01.gif|200px|Test Animated gif]] -->
<!-- [[Image:LSU_Stable.animated.gif|74px|Test Animated gif]] -->
[[Image:pivotingBox03.gif|right|250px|Test Animated gif]]
* Use the "Explore" feature of VisTrails to sample a parameter range and thereby generate a sequences of spreadsheet images.
** For example, vary the Camera's Azimuth by 3 degrees between images.
** In order to ensure a reasonably good size/resolution for each image, we have found it beneficial to generate at most five images per "Explore" session.

* After viewing the spreadsheet results, use the spreadsheet's "Export/Separately" menu option to dump the image sequence into a new (otherwise empty) file folder.  
** If the images are laid out across the spreadsheet horizontally, by default, VisTrails will name the files:  a1.png, a2.png, a3.png, etc.
** If the images are laid out across the spreadsheet vertically, by default, VisTrails will name the files:  a1.png, b1.png, c1.png, etc.

===Inside Excel & Paintbrush===
* Construct a 2D x-y plot with all of the detail that you would want to put in a single printed journal figure.
* Take a snapshot of the figure:
** Place the mouse cursor somewhere on the boundary of the figure frame;
** CTRL-mouse-click generates a drop-down menu; selecting "Save as Picture &hellip;" copies a bitmapped image to the Mac's clipboard.
* Open "Paintbrush" and paste the image into an otherwise blank window; save the image into the desired file folder.
* Return to Excel; make the necessary changes in spreadsheet parameters to construct the next 2D x-y plot for the desired movie sequence; as before, save this new image (using a different, but preferably sequentially numbered) name into the desired folder.

==Creating the Animation==
===Animated GIF===
====Using ''convert''====
* Via the Mac's terminal window, change directories into the folder that contains the image sequence.  
* As necessary, rename image files in order to define the desired image sequence:
** The "convert" program (see next instruction step) expects the file names to be in a consecutively numbered sequence;
** Assuming PNG-formatted image types, we recommend using the numbering sequence:  a01.png, a02.png, a03.png, etc.
** If you want a smooth back-and-forth animation loop and you are starting with 9 images (numbered a01 thru a09), make additional copies of images such that the entire animation is: 1-2-3-4-5-6-7-8-9-8-7-6-5-4-3-2.  But the last seven images should be ''named'' a10.png, a11.png, a12.png &hellip; a16.png.
* Type one of the following two commands (2nd one preferred!):
<pre>convert -set delay 3 -colorspace GRAY -colors 16 -dispose 1 -loop 0 -scale 50% *.png Output.gif</pre>
<pre>convert -set delay 10 -colors 1024 -dispose 1 -loop 0 -scale 100% *.png Output.gif</pre>

* Related information:
** I initially extracted the first of these recommended "convert" instructions from [http://pages.uoregon.edu/noeckel/MakeMovie.html Jens N&ouml;ckel's web site].
** My Mac contains a manual on this "convert" instruction (man convert); it points out that, "The <b>convert</b> program is a member of the ImageMagick(1) suite of tools."
** The Mac's "convert" manual also refers to a [http://www.imagemagick.org/script/convert.php convert website].

* Finally, rename the "Output.gif" file to something that better identifies the content; upload the renamed "Output.gif" file to the VisTrails wiki site; and insert it into the desired wiki page just as you would insert a single image.

====Using Keynote====
On 30 May 2021, I acquired a new iMac to replace the (desktop) Mac Pro that I have relied on since 2010.  This new system's "Big Sur" (v11.4) macOS encounters an error when I try to execute ''convert''; I think this is because convert's binary executable is incompatible with my new iMac's CPU hardware.  [https://support.apple.com/guide/keynote/create-an-animated-gif-tan30ff1f63c/mac Online discussions] appear to recommend that animated gifs be constructed using Apple's "Keynote" (''aka'' Powerpoint) utility.
* Create a new, blank Keynote file;
* Paste (drag-and-drop) the first gif image onto the first slide of this new file;
* Add a second, blank slide to the Keynote file, then paste the 2nd gif image onto this slide;
* etc.; [make sure each image sits in precisely the same position on each slide]
* Under Keynote's "File" dropdown menu, 
** choose "Export to ... Animated gif ..."
** identify the range of slides (e.g., 2 thru 28) that are to be incorporated into the animation, and the desired frame rate;
** click "Next", etc.

=Related Discussions=