[GRASS-dev] Re: Nviz animation wish

[Michael Barton]

This discussion has been enlightening. However, it might be good to get back
to the original wish that prompted it.

Currently, in the NVIZ animation panel, you can set key frames and NVIZ will
interpolate between the key frames to produce an on-screen animation. It
will optionally save an image sequence (as per discussion below) that can be
transformed into an animation file by 3rd party software. This is fine.
However, the only characteristics animated are the position and orientation
of the 2.5D rendering.

What I asked was if this could be enhanced to also include the color and
other features of the rendering. That is, keyframe 1 shows the landscape
with one color drape, keyframe 2 shows it in a second color drape, and
keyframe 3 shows it in a 3rd color drape. Then when the animation is run,
you would see the landscape changing smoothly from color 1 to 2 to 3. If
desired, you would still output these to an image sequence (rather than to
an mpeg or other animation file). Similarly, could it handle something like
z-exaggeration or lighting direction?

So, does the Togl command that drives the keyframe animation now also accept
color rendering (and other) information, or only position and orientation?

Michael


On 1/26/07 12:42 PM, "Maris Nartiss" <maris.gis at gmail.com> wrote:

> 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>
> 
> 

__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton