We are using InnoSetup to generate the installer of Substance Painter.
The whole set of parameters that can be used with the installer is available here: http://www.jrsoftware.org/ishelp/index.php?topic=setupcmdline
Installing in silent mode (via command line)
The flag to use to perform a silent install is "/SILENT". You can also use the "/NCRC" flag to skip the CRC (verification) of the package.
The installation path must be using single backslash character to separate folders, otherwise the InnoSetup installer will not recognize the path.