[GRASS-user] Regarding NVIZ and d.slide.show

[Hamish]

yuri bay wrote:
> I am trying to use the NVIZ for simulation animation and is wondering
> if it can be used for the following scenario: to move a point from
> one position to another for a period of time, for a series of
> different positions. I know  NVIZ can be used for 3D animation, but
> what about the 2D vector-based animation just mentioned?  If NVIZ can
> be used for this purpose then would anyone tell me where can I find
> the information on how to use it?

I have now added some examples to the Wiki animations page:
  http://grass.gdf-hannover.de/wiki/Movies

    * 1 Q: How to construct high-quality MPEG-4 movies (animations)
           from a series of still frames?
    * 2 Q: How to generate an animated GIF, FLI, or MNG?
    * 3 Q: How to create dynamic surface movies in NVIZ
    * 4 Q: How to animate a time series of raster maps?
    * 5 Q: How to animate a series of maps, including decorations?
    * 6 Examples
          o 6.1 Animate on screen
          o 6.2 Animate to files
          o 6.3 Encode as animated GIF
          o 6.4 Encode as animated PNG (MNG)
          o 6.5 Encode as FLI
          o 6.6 Encode as MPEG-4 Xvid


> By the  way, have anyone got the information on how to use
> d.slide.show? The explanation in the GRASS help is not really helpful.

Spearfish:
 d.mon x0
 d.slide.show prefix=elev




Problem -- mencoder doesn't like PPMs created with the GRASS PNG driver:

$ file ganim_001.ppm
ganim_001.ppm: Netpbm PPM "rawbits" image data

$ ls -l ganim_*.ppm | wc -l
22

$ mencoder "mf://ganim_*.ppm" -mf "type=ppm:fps=5" -o ganim2.avi \
   -ovc xvid -xvidencopts bitrate=1024
MEncoder 1.0pre8-3.3.5 (C) 2000-2006 MPlayer Team
[...]
success: format: 16  data: 0x0 - 0x0
[mf] search expr: ganim_*.ppm
[mf] number of files: 22 (88)
[demux_mf] unknown input file type.
============ Sorry, this file format is not recognized/supported =============
=== If this file is an AVI, ASF or MPEG stream, please contact the author! ===
Cannot open demuxer.
Exiting...



Using PNG files work fine (see wiki example).



Hamish