Cone2: 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/Cone2 - from package: vtk-examples

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

Error in other languages:
Cone2: bevel nie gevind nie
Cone2: comandă negăsită
Cone2: comando não encontrado
Cone2: commande introuvable
Cone2: command not found
Cone2: käsku ei ole
Cone2: không tìm thấy lệnh
Cone2: komanda nerasta
Cone2: Kommando nicht gefunden.
Cone2: kommandot finns inte
Cone2: komut yok
Cone2: nie znaleziono polecenia
Cone2: níor aimsíodh an t-ordú
Cone2: no se encontró la orden
Cone2: no s'ha trobat l'ordre
Cone2: opdracht niet gevonden
Cone2: parancs nem található
Cone2: perintah tidak ditemukan
Cone2: príkaz nenájdený
Cone2: příkaz nenalezen
Cone2: команда не найдена
Cone2: командата не е открита
Cone2: 命令找不到
Cone2: コマンドが見つかりません