osgocclusionquery: 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/osgocclusionquery - from package: openscenegraph

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

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