When the plug-in is started up, it will automatically create an out-of-process session to use.

The automatic session uses a named pipe with the name of HEMAX_AutoPipeServer.

There is also the option to manually connect to a specified session via a Thrift socket or a Thrift named pipe. This is done via the use of a thin client that is included in Houdini Engine. In short, this thin client allows the main Houdini Engine processing to happen in a separate process (outside of the 3ds Max process). The plug-in can use either a TCP socket or a named pipe to communicate between the 3ds Max process and the Houdini Engine process.

Note that creating a manual session requires a Houdini Engine server process that the session can communicate with. For more information about running HARS, please visit the Houdini Engine documentation

In order to use socket sessions, a Houdini Engine server must be manually started with a known port on a known machine. Then, that host and port information can be used in the plug-in to connect to that session.

The easiest way to create a Houdini Engine server is to create a debugging session within Houdini. This can be found under the Windows → Houdini Engine Debugger menu found within Houdini.

A named pipe connection is the recommended method when starting the thin client on the same local machine. Just like a socket session, a Houdini Engine server must be manually started with a known pipe name. That pipe name can then be used in the plug-in to connect to that session.

You can also connect to an existing Houdini Engine server (HARS or Houdini SessionSync) using a shared memory session. The shared memory name, buffer type, and buffer size must match the configuration of the server or errors will occur.