Joined: 17 Apr 2013
|Posted: Fri Dec 27, 2013 6:54 pm Post subject:
Having trouble making no-data transparent in vpb database
I could use a bit of advice on how to properly format my osgdem parameter to ensure that boundary areas of the quad aren't interpreted as black, but instead as completely transparent.
I use vpb to generate terrain for use with an osgEarth application.
I've created an earth.
I'm creating a high-resolution inset based on a widely available dataset.
I receive the files, convert them in gdal and strip extra color bands, warp them in gdal using the -dstalpha parameter to make sure that all boundaries are transparent (otherwise I get a nice repeating pattern of very thin black strips), and create overviews.
I then use the following command:
osgdem --geocentric --TERRAIN --notify-level WARN -t ../warp --default-color 0,0,0,1 -O Compressor=zlib -o myoutputfile.osgb
The database processes correctly, but each lod file fills in black anywhere there is no data. This means that when I overlay the terrain db on top of another data set, it looks horrible.
I could use a parameter within osgEarth to make black a transparent value, but that doesn't work as then you have lots of little transparent specks all over the place.
I've attached two images that help demonstrate the issue. If someone could help me configure my parameters correctly, I'd appreciate it greatly.