[GRASS-user] Trento3D screenshots redone

[Hamish]

> - interpolate dem to highres (I used 2m pixels) with r.surf.rst

is this really needed? g.region res=2 & NVIZ will smooth (or do you see
flat patches/aliasing grid then?).


> > If not, is it possible to use the Trento dataset to create one? One
> > possible use if other details can be worked out is to create
> > maps of flood inundation to show buildings affected by flooding. 

Yes! worldwide problem of all coastal & riverside cities. Trillions of
dollars at risk. ([ed.] compare with the cost of dealing with CO2 issues
now) This sort of thing (esp. animated) is very effective for
presenting dry model results to the public & policy makers.


> OK, I couldn't resist :-)
> 
>  http://mpa.itc.it/markus/grass61/demos/rlake/
>  -> see at bottom for new screenshot with flooding
>     (needs r.lake which is still not in CVS...)
> 
> > I understand one must have the 
> > building data (how was *that* obtained?).
> 
> The Trento municipality was going out and digitizing all builings.
> Another option is to digitize building footprints from orthophoto
> (v.digit) and assign a typical height to each building.

trick: You don't need actual height of buildings, just number of floors.
(how you did Trento version 1 Markus?)
Interns can do orthophoto tracing work :)  .. LIDAR ..

> > This type of presentation is 
> > very effective in capturing the imagination (as it were) of those 
> > possibly affected by flooding.
> 
> Fully agreed and done. Except for r.lake everything is in
> 6.1-CVS.
> 
> Only the merge of the flood map with orthophoto could be better
> (r.mapcalc will kill the color table, r.patch as well). In February
> I did a trick in nviz (see earlier flood screenshots) which I
> don't remember today (maybe I loaded the DEM twice or so).

Loaded r.lake surface as a second raster?

A trick: in NVIZ make a New constant surface of 0.0, set color to
something white-blue, set transparancy to ~1/2, and raise-lower level
with "Position" button's z-slider. I never seem to get surface order
correct, "Draw Current" is your friend.

e.g. sea level lowered to ice-age/old tectonic levels to show ancient
shore line position:
  http://bambi.otago.ac.nz/hamish/pics/sill_iceage_115m.jpg


Get height from high-water mark of last 100yr flood? (surely recorded)



Hamish