Try omitting the s_srs portion of the gdalwarp command to see if that makes any
difference.
I believe dted files will need to be reprojected as well since VPB builds the
database using the source data coordinate system.
-Shayne
-Original Message-
From: osg-users-boun...@lists.openscenegraph.org
[mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Atilla Selem
Sent: Friday, May 06, 2011 12:39 AM
To: osg-users@lists.openscenegraph.org
Subject: Re: [osg-users] [vpb] Flat Database Generation in Meters reallyshocked
me when i load it to my osg application..!!!
Hi Shayne,
Hi Glenn,
Thanks for ur kind replies..
Shayne,
As you know MyTerrain.tif file projection info was;
Geographic ( Latitude / Longitude )
[N:36, E128] [N:38, E130] is in Utm Zone 52
Datum : WGS84
Unit : Arc degrees.
i tried to reproject MyTerrain.tif file using ur gdalwarp command like this..
gdalwarp -s_srs proj=latlong +datum=WGS84 -t_srs proj=utm +zone=52
+datum=WGS84 MyTerrain.tif MyTerrainUtm.tif
command prompt displayed such an error;
ERROR 1 : Translating source or target SRS failed:
proj=latlong +datum=WGS84
Is gdalwarp command true in terms of parameters?
And one more question.. Should i run gdalwarp command for each of my dted-2
files which have Geographic projection before using osgdem?
Thanks a lot,
Atilla.
S2LR wrote:
Try using the following to reproject your data...
gdalwarp -s_srs proj=latlong +datum=WGS84 -t_srs proj=utm +zone=11
+datum=WGS84 infile outfile
Do this before using osgdem on your data files. UTM zone selection will be
dependent upon where your lat/lon is...
-Shayne
-Original Message-
From: [mailto:] On Behalf Of Atilla Selem
Sent: Thursday, May 05, 2011 11:09 AM
To:
Subject: Re: [vpb] Flat Database Generation in Meters reallyshocked me when
i load it to my osg application..!!!
Hi Glenn,
Thanks for the tip.. but i really need to know,
Where should i do reprojection? In my dted-2 files and/or in my GeoTiff.file
(since their projections are both Geographic - Lat/Lon) before executing
osgdem?
Or should i do re-scaling or whatever after i load terrain in osg application?
And What tool or command option should i use to reproject to UTM?
thanks in advance..
Atilla.
Glenn Waldron wrote:
Atilla,osgdem is creating your model in what's called a plate carre
projection -- in which degrees are simply reinterpreted as meters. That is
why your 2x2 degree cell is appearing as 2x2 meters.
You need to reproject into a proper projected spatial reference system
(like UTM) to get the correct extents.
Check the bottom of this page for tips:
http://www.openscenegraph.org/projects/osg/wiki/Support/UserGuides/osgdem
(http://www.openscenegraph.org/projects/osg/wiki/Support/UserGuides/osgdem)
Glenn Waldron / Pelican Mapping / @glennwaldron
On Thu, May 5, 2011 at 12:25 PM, Atilla Selem () wrote:
Hi,
i have tried to generate a terrain (.ive) database using osgdem
commandline options in order to buid a flat database where coordinates
are in meters. After successfull generation i put that terrain in my osg
application and really shocked! Before telling you what i saw as the
output let me tell you my inputs.
- i have four Dted-2 elevation file,
- i have one GeoTiff image which is successfully mapped on dted files.
- Dteds are starting (from 36N, 128E to 38N, 130E). So there are 4 1x1
degree cells [ Total size is 2x2].
- GeoTiff image also extends from 36N, 128E to 38N, 130E. So it covers
[2x2] elevation file without no problem.
Dted and Image Coordinate Systems are:
Geographic ( Latitude / Longitude )
Datum : WGS84
Unit : Arc degrees.
after putting dteds and image in seperate folders ( MyDted, MyImage ) i
executed the following vpb command to generate my flat database.
- osgdem -t MyDted -d MyImage -l 8 -v 0.1 -o MyTerrain_Flat.ive
after executig above line and loading Terrain_Flat.ive on my osg
application it was really difficult to find where is MyTerrain_Flat.ive
on my view.
When i zoom in What i saw was a 2x2 meter flat database in osg size.
!!!It was located on x = 128 , y = 36 on my view according to ( 0,0,0) of
my scene!!!
Real size of Dteds of Image was 178 km in Easting and 221 km in
Northing.. i have checked size and everythings was ok with Dted and Image.
Now the question is
1 - Is there a problem with vpb when creating flat database in meters?
2- Have i missed a command line option?
3- Why is the generated terrain covers 2x2 meters although it is 178 x
221 km in real size?
4- Why it is located in x = 128 , y = 36 ? Those were Lower Left Lat/Lon
coordinates of dteds and image file?
4- Isn't it possible to generate real size flat terrains in meters in
x,y,z using vpb?
Any help is really appreciated...
...
Thank you
