cube: 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 CentOS possible default full paths are:

/usr/bin/cube - from package: cube
/usr/bin/cube - from package: vtk-examples

You may install the required package with command yum install {package}

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