[GRASS5] working on g3d

[Alfonso Vitti]

ok, more or less, this is where we are:

wish list 
---------

.    r3.flow (almoste done, Jaro Hofierka)
     3D flowtracing module
.    s.volt.rst (almost done, Jaro Hofierka)
     4D interpolation with saviong time series of g3d volumes or 2d
     intersection files
.    link/conversion to and from 2D data
     (merging 2D files to 3D file and splitting 3D file to 2D layers)
.    merging "elevation" 2d surface to 3d file
     1 = air (?)
     0 = surface (?)
     -1 = soil (?)
     (e.g. geological fault surfaces)
.    visualization - NVIZ - support of 3D raster
     (integration of sg4d or r3.showdspf functionality?)
     (Tomas Paudits has started on this)
     (porting sg4d to i686-pc?)
.    some sort of user interaction with 3d data on monitor
     (something like d.what.rast)
.    support of time series (needed also for 2d data), naming
     conventions?
.    data conversions between 3D vector (Grass5.1) and 3D raster format
.    r3.stats
.    r3.recode
.    r3.what
.    r3.out.v5d/r3.in.v5d with support of 5d data, i.e. time series of
     3d data merged to v5d animation file
.    r3.proj?
.    xganim - support of 3d data animation?
.    add the possibility to define in the volume "boundaries surfaces"
     (support to regionally restricted interpolation/analysis)
     [keeping soil horizon boundaries or stratifications]
.    hist files
.    r3.mapcalc add the capability to use also 2d-raster
.    r3.mapcalc add absolute cell reference
.    temporal series and 4D data format, compression...
.    export to netcdf format
     (a 2D version already exist, written by Alessandro Frigeri,
     Generic Mapping Tools and Explorer-OpenDX are supported)


g3d libraries
-------------

two tipe of functions can be defined:
tiles-functions and no-tile-functions

.    now (I hope) all the parameters in the no-tile-functions are called
     in the order:
     rows, cols, levels
		 iven if sometimes the notation
		 y, x, z
		 is used
.    the parameters in the tile-functions are called in the order:
     x, y, z
     iven if sometimes the notation
     cols, rows, levels
     is used


known bugs
----------

.    r3.mapcalc crash increasing the number of levels (error in
     G3d_getTilePtr)
.    r3.mask crash (error in G3d_getTilePtr)
.    r3.showdspf some parameters don't work
.    r3.out.v5d always/sometimes(?) it reverses t-b, n-s order


discussion
----------

.    extend the new r.mapcalc to a third dimension and replace the
     current r3.mapcalc
.    for loops: levels, rows, cols
     (once for all, let's define them)
.    do the tile-functions (see above) have to use x,y,z notation or
     could/should it be
     moved to rows,cols,levs?
.    tiles support/use/performance
.    update docs, bugs, todo files in src.contrib/GMSL/g3d


Alfonso