osgconv: command not found

Have You tried accessing the binary with the full path?

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/osgconv - from package: openscenegraph

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