osgearth_city example projection problem

Hello;

I am trying to execute the osgearth_city example. But I get SpatialReference and projection error messages as seen on the attached picture. I did not do any changes on either the "osgearth_city.cpp" file or the .earth files. Most probably boston buildings are not rendered because of this error. What might be the problem? How can I solve it?

You might need to set your GDAL_DATA environment variable to point to the gdal-data folder in your GDAL distribution. It probably can't find the proj4 data files.

Thank you Glenn. Now there is no problem with the projection. But there is a rendering problem. When I tried to see the street level the thing in the picture showed up.