render: 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/render - from package: raster3d

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

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