osgviewerQt: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/osgviewerQt - from package: openscenegraph

You may install the required package with command apt-get install {package}

Error in other languages:
osgviewerQt: bevel nie gevind nie
osgviewerQt: comandă negăsită
osgviewerQt: comando não encontrado
osgviewerQt: commande introuvable
osgviewerQt: command not found
osgviewerQt: käsku ei ole
osgviewerQt: không tìm thấy lệnh
osgviewerQt: komanda nerasta
osgviewerQt: Kommando nicht gefunden.
osgviewerQt: kommandot finns inte
osgviewerQt: komut yok
osgviewerQt: nie znaleziono polecenia
osgviewerQt: níor aimsíodh an t-ordú
osgviewerQt: no se encontró la orden
osgviewerQt: no s'ha trobat l'ordre
osgviewerQt: opdracht niet gevonden
osgviewerQt: parancs nem található
osgviewerQt: perintah tidak ditemukan
osgviewerQt: príkaz nenájdený
osgviewerQt: příkaz nenalezen
osgviewerQt: команда не найдена
osgviewerQt: командата не е открита
osgviewerQt: 命令找不到
osgviewerQt: コマンドが見つかりません