[Qgis-user] orthographic projection for raster not working

[Andre Joost]

Am 24.08.2014 16:15, schrieb muhali:
> I am trying to project the Natural Earth raster (e.g.
> www.naturalearthdata.com/downloads/50m-raster-data) using the following
> parameters:
>
> +proj=ortho +lat_0=0 +lon_0=0 +x_0=0 +y_0=0 +ellps=WGS84 +units=m +no_defs
>
> It gives me nothing (white space). If I do the same for corresponding vector
> data (e.g. www.naturalearthdata.com/downloads/50m-physical-vectors)
> everything works.
>

The ortho projection does not cover the whole world, only the visible 
half. To avoid artefacts, you have to crop your data source to that 
visible half. I have described here how you can do it:

<http://gis.stackexchange.com/questions/70207/where-did-the-polygons-go-after-projecting-a-map-in-qgis>

HTH,
André Joost