I recently installed ROOT ver. 5.20 into ubuntu.
Install went well, and I was able to perform basic task
such as read .root file with TFile, pop an canvas with TCanvas etc.
When I tried to use TGLViewer3D, TGLScene etc, root
complains that TGLViewer3D is not defined, and there is no
such file as TGLViewer3D.h
Do I need to do something special at installation stage to
install TGL classes ?
Apparently your root was compiled without OpenGL support.
This probably means that you need the packages that provide the GL header files and/or shared libraries (you need libGL and libGLU).
If you do
root-config --features
and ‘opengl’ is not listed, that’s it.
When running ‘configure’ pay attention for what checks are being performed related to GL.