$ sudo apt-get remove g3dviewer 

Uninstall g3dviewer including dependent package

If you would like to remove g3dviewer and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove g3dviewer 

Use Purging g3dviewer

If you use with purge options to g3dviewer package all the configuration and dependent packages will be removed.

$ sudo apt-get purge g3dviewer 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove g3dviewer 

See Also,