Empty regions in gnomonic projection (no data)

[ajuvolkov]

Hello. I tried to project Earth on the cube faces.

​http://www.progonos.com/furuti/MapProj/Normal/ProjPoly/Foldout/Cube/cube.html

To do this I use a image with Earth map in Plate Career projection and tools: gdal_translate and gdalwarp. I do this command to prepare GeoTIFF source:

gdal_translate -a_ullr -180 90 180 -90 -a_srs "+proj=longlat +lat_ts=0 +lat_0=0 +lon_0=0 +datum=WGS84 +ellps=WGS84 +no_defs" plate.png plate.tif

Then I do this to obtain cube faces:

gdalwarp -te -6378137 -6378137 6378137 6378137 -t_srs "+proj=gnom  +lon_0=0   +lat_0=0   +datum=WGS84" -tr 20000 20000 -overwrite plate.tif px.tif 
gdalwarp -te -6378137 -6378137 6378137 6378137 -t_srs "+proj=gnom  +lon_0=180 +lat_0=0   +datum=WGS84" -tr 20000 20000 -overwrite plate.tif nx.tif
gdalwarp -te -6378137 -6378137 6378137 6378137 -t_srs "+proj=gnom  +lon_0=90  +lat_0=0   +datum=WGS84" -tr 20000 20000 -overwrite plate.tif py.tif
gdalwarp -te -6378137 -6378137 6378137 6378137 -t_srs "+proj=gnom  +lon_0=-90 +lat_0=0   +datum=WGS84" -tr 20000 20000 -overwrite plate.tif ny.tif
gdalwarp -te -6378137 -6378137 6378137 6378137 -t_srs "+proj=gnom  +lon_0=0   +lat_0=90  +datum=WGS84" -tr 20000 20000 -overwrite plate.tif pz.tif 
gdalwarp -te -6378137 -6378137 6378137 6378137 -t_srs "+proj=gnom  +lon_0=0   +lat_0=-90 +datum=WGS84" -tr 20000 20000 -overwrite plate.tif nz.tif

The problems are encountered in polar regions and 180 degrees of longitude areas. See files nz.tif, pz.tif and nx.tif.

Whats wrong?

[ajuvolkov]

Plate Carree projection source image

[ajuvolkov]

Trget file with polar region with empty area (+lon_0=0 +lat_0=-90)

[ajuvolkov]

I found this tickets: http://trac.osgeo.org/gdal/ticket/642 and tried to use options -wo SOURCE_EXTRA=100 -wo SAMPLE_GRID=YES and got a good result. But in this issue says that the problems have been fixed in code. Why it doesn't work in v 1.9.0 without using the above flags?

[Even Rouault]

This ticket has been automatically closed because Trac is no longer used for GDAL bug tracking, since the project has migrated to GitHub. If you believe this ticket is still valid, you may file it to ​https://github.com/OSGeo/gdal/issues if it is not already reported there.