[GRASS-dev] Re: Nviz animation wish

Maris Nartiss maris.gis at gmail.com
Fri Jan 26 14:42:34 EST 2007


Hi all,

IMHO we should NOT add a yet another dependency for GRASS especialy
that duplicates already working utilities with not-as-good in-house
wonder. We do not have enough manpower to implement YetAnother video
encoder.

As Glynn notes, creating animation from image sequence is better. One
of best things of encoding image series into movie is that You can
play around with various video encoding options to find best
quality/size ratio for Your artwork without need to recreate
(rerender) every scene in Your animation. Stacking together all PNG's
in one movie with mplayer's encoder is described in GRASS wiki [1]
with basic options that You will need. Mplayers encoder (mencoder)
offers many other options - lot more than may offer any GRASS encoding
tool.

The hardest part of creating animations is getting those PNG frames to
disk - controling camera and saving result. When I last time had to
make movie in nviz, I ended with TCL script controlling camera movment
and orientation, as, unfortunately, I find built-in nviz tools hard to
use :(
IMHO it would be better to improve nviz animation tool (one and not
many) and leave video encoding to other apps. Unfortunately I had no
time to check nviz progress in this area or to study new documentation
about this topic (FOSS4G06 demos) - maybee my opinion is outdated ;)
Anyway - You can check animations created frame by frame and then
encoded with mencoder here [2].

Just my 0.02 Ls,
Maris.

[1] http://grass.gdf-hannover.de/wiki/Movies
[2] http://mpa.itc.it/markus/grass61/demos/rlake/

2007/1/26, Glynn Clements <glynn at gclements.plus.com>:
>
> Ultimately, the only sane approach to generating animation is to write
> out a sequence of image files then use a dedicated encoding program
> such as ffmpeg. Video encoding is a complex task with many parameters.
> Any built-in encoding functionality is inevitably going to do a
> half-baked job.
>
> --
> Glynn Clements <glynn at gclements.plus.com>




More information about the grass-dev mailing list