Could someone clarify the difference between TK and TCL….
It seems to me that TK is TCL with a bunch of UI extensions?

In any case, how come Houdini allows the user to interact with the TK console and with Houdini master at the same time, while the TCL does not?

In other words: If I type: tcl in my textport, tcl takes over textport, but if I type tk I can still use the textport?

Hello!

tk is the ToolKit for tcl and yes it is “only” a bunch of UI extensions. If you type tcl in the textport (normally with an argument specifying a script), Houdini assumes, that you want to execute a script and halts its execution and waits til the end of the process. This is also called modal execution. In the case of the tk command houdini assumes, that the script you give him builds up a UI and the script is not executed in an atomic way. This is non-modal execution, where the script and Houdini execute in parallel. For example the script builds up a window with a button and the user clicks on it. Now the script sends a message to Houdini to execute some commands.
You can compare the tcl and tk commands with starting programs in a Unix-shell with or without ‘&’. To sum up, the tcl command waits until the end of the executed script, while the tk command continues execution of Houdini.

Hope this was not too confusing.
Frank

I gotcha …