Cone3: 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 CentOS possible default full paths are:

/usr/bin/Cone3 - from package: vtk-examples

You may install the required package with command yum install {package}
Error in other languages:
Cone3: bevel nie gevind nie
Cone3: comandă negăsită
Cone3: comando não encontrado
Cone3: commande introuvable
Cone3: command not found
Cone3: käsku ei ole
Cone3: không tìm thấy lệnh
Cone3: komanda nerasta
Cone3: Kommando nicht gefunden.
Cone3: kommandot finns inte
Cone3: komut yok
Cone3: nie znaleziono polecenia
Cone3: níor aimsíodh an t-ordú
Cone3: no se encontró la orden
Cone3: no s'ha trobat l'ordre
Cone3: opdracht niet gevonden
Cone3: parancs nem található
Cone3: perintah tidak ditemukan
Cone3: príkaz nenájdený
Cone3: příkaz nenalezen
Cone3: команда не найдена
Cone3: командата не е открита
Cone3: 命令找不到
Cone3: コマンドが見つかりません