[wellylug] Possible project of interest?

Wood Brent pcreso at pcreso.com
Tue Jan 27 17:23:09 NZDT 2004


--- "E.Chalaron" <e.chalaron at xtra.co.nz> wrote:
> > Is anyone here interested in such a project, or able to provide
> > support/resources which could be useful?
> 
> Me .......... 
> Though why not using GMT ? It is simple to use.

Agreed, & I have used it to make maps from the data. It isn't the best tool for
managing the data though, & this volume of data does require managing. Also,
while GMT can draw the (reformatted) vectors OK, you need to make grdfiles for
the DTM & shading, & while this is simple enough to do, the grd resolution
depends on the map scale you want to produce, & you may need a DVD for each
grdfile if you want high resolution!

> What is the grid resolution and do you plan to keep the NZ grid system or go 
> to decimal degres/minutes ? I actually would be keen developping bash scripts

The source vector data is basically NZMG (or the new 2000 projection)
coordinates as single points or series linked to quite a few attributes. (Part
of the reason for not using GMT as the main tool- no real attribute support,
try naming roads. Tho the beta V4 of GMT may improve GMT's capabilities in this
area) 

I'd prob look at using proj (or GRASS to convert from NZMG to lat/long coords
with a datum of WGS84 (with longs from 0-360 to fit the Chatham's etc...) to
make a more generic dataset. Anyone requiring any other datum/projection could
reproject as required. I'm not sure how far docs for such a dataset should go.
Discussions of geoids & projections might be a bit much.

As it is pretty easy for GMT users to extract the elevation contours as XYZ
points to build a gridfile DTM from, I'd sooner provide the source data & let
users do what they want.

No reason it couldn't be used with GMT to do what you suggest though. I think
GRASS, JUMP or QGIS as OpenSource GIS tools would be more readily useable with
the data, even if they don't easily produce printed maps with the quaity of
GMT.
(I'm open to be conviced otherwise- at this styage my interest is in providing
the data, the application is up to the user)

To create a full OpenSource GIS app/data CD set with this volume of data (some
26 CD's as uncompressed Mapinfo MID/MID files, prob a couple of CD's as bzipped
shapefiles) is pretty ambitious. 

I reckon get the data done first :-)

> 
> to convert 3D views in videos... well I'll probably need some help for a 
> couple of things I am not sure of.

Could be neat to show what can be done with it, tho NVIZ in GRASS or OpenDX
might simplify the creation of flyby's & such. 

Were you aware Paul Wesel's GMT course in March is supposed to include
producing animations from GMT?



Thanks for the input,

  Brent




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