Hints for making a video or QuickTime animation electronically
To make a video or simply supply images for one
In any application, use the snapshot function to grab your viewport
image and save it to an rgb file.
In PATRAN, you can you any of the available image functions to save an image
to a file. You can also use a script to dump several images sequentially.
Some hints for making the finished product look good on a video:
(Contact Video Applications Group (LaRC only)
for the most current info...)
- Use images sized 648 x 486 if possible. You can get the image
sizing you need easily by sizing the PATRAN viewport.
- Avoid putting anything worthwhile near the edges of your image
since it will inevitably be clipped off by some monitors. In
video, they define a safe area in the middle of the screen with
an "unsafe" perimeter that can be as much as 10% of
the screen space (there goes your resolution yet again). PATRAN
automatically puts the spectrum at the edge. You can't move it,
but you can take it off, and provide the spectrum as a separate
rgb file, to be put on any defined segment of the video. As far
as I could tell, you have to create the plot, clear the spectrum
using ga_viewport_spectrum_set, then save the rgb file using dump_rgb,
as shown in the session file lines above. The image will jump
back and forth on your screen as it plots with and without the
spectrum, but all images saved as rgb files will be without the
spectrum and in the same place.
- Avoid the color red. NTSC has severe problems with fully
saturated reds.
- Avoid fully saturated colors so if your color range for each
red, green, and blue value is 0-255 then reduce it by 75% (i.e.
0-191). This can be done by changing the color table before you
start taking images.
- Do not put any non-moving text (a time counter is an example
of moving text) on the image since the fonts are most likely not
video compatible and will have to be retyped in by the video editor.
- Avoid line widths of a single pixel and use at least 2 or
more pixels to reduce moire patterns and video crawl. This may
not be an option that you have control over in PATRAN.
- Use filenames like "junk.001.rgb" - "junk.123.rgb"
so that "ls -l" will list the files in order.
The images will never look as good (especially on VHS tape) as
they do on your workstation screen, but these hints do help.
QuickTime animation for use on Web pages
You can also have the finished video turned into a QuickTime animation
for use on a Web page. Video
Applications Group (LaRC only) (was DVAL) does this. Their process
(at least for one sequence) was:
The movie was captured from Beta tape via a Targa1000 pro capture
board. It was then edited in Adobe Premiere v.4.2.1. From there it was
exported to Media Cleaner Pro.v2.5.1. where it was compressed using the
CinePak code in to a Quicktime 3.0 movie. The frame rate was
10 frames per second (and there's several variables you can set within the
compression).
When you place these on a Web page, viewers using Mac or Windows 95/NT will need
the QuickTime 3.0 software to see the animation. You can download this software from
Apple (external link).
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