[Dorico 3.5] Clarification on "Init" Expression Map Switch

I was wondering if someone could clarify the exact way in which the “Init” switch in an expression map functions? I’m trying to set one up for the BBCSO plugin, and for the life of me I cannot get it to work, either on resetting playback, going back to the beginning with the play head, or restarting Dorico.

For specifics, I’m trying to add a CC switch on CC#7 to a value of 75 so that BBCSO’s volume is initialised to 0dB by default.

Welcome to the forum, jrkulmer. Certainly in theory I would expect this to work: every time you start playback, the actions defined in the ‘Init’ switch should be output. Do you want to attach a (zipped up) project here containing your expression map so we can take a look?

Cheers for the quick response! Sure, please find attached. I had a look at the doricolib file when exporting a library - and after changing the file extension to xml - it looks as though the is generated as empty. Is there some step in associating the expressison map with a particular plugin that I’ve missed?

For clarification I have assigned the expression map to the VST instance via the endpoint configuration dialog. Also, I’ve been testing the CC switch with a value of 0 as it’d be more obvious when it works.
Expression Map Init Problem.rar (654 KB)

The Init switch will send CCs and PCs at the start of playback. However, the CC7 is also sent by the Dorico MIDI mixer - press the MIDI button at the top of the mixer and then you can set the values there that will be sent for CC7 and CC10.

Thanks for the info. Whilst I’m grateful for now knowing this, I must say I think you should address this limitation in a subsequent release, as it is totally undocumented and not at all apparent from the user interface that this limitation exists.

I would suggest either forbidding CC7 and CC10 in the Init switch (with explanation in the UI), or enabling their use by overriding the signals used by the mixer.

Also, as you can see in the screenshot attached, there is no indication in the mixer that a particular CC change is initiated at the start of playback by the mixer. The only information displayed is that MIDI information is being fired onto the particular track, not which signals, or which CCs.

Its not obvious how to use this “MIDI” fader in the mixer to set control change parameter values, but I can do that without issue by drawing them in on the Play screen. The context of the issue is setting initial CC values automatically for a large orchestral template, having to manually set the values for every track is not a long-term solution!

For the time being I’ll change the CC parameter that the plugin uses for volume so I can manipulate it via a different CC, but it would be interesting to know your thoughts as to the long-term solution to this.

In an application as complex as Dorico, it’s just not possible to document every caveat, or provide UI and warning messages for every possible situation that a user may encounter. Every extra option and error message requires substantial work to implement, test and localise into 9+ languages. We try to find ways to minimise ambiguities, but this isn’t always possible. Especially as the application is developing at a very rapid rate, and it’s not until users have been using the application for a while before patterns of usage emerge. To many users familiar with DAWs or other notation packages, it’s expected that a MIDI mixer will send the MIDI volume and pan controls (CC7, CC10).

Longer term we anticipate that the mixer and automation lanes will be tied more closely together. For the moment though, you can add a CC automation lane to control CC7 over time. Any automation you draw there will prevent the mixer value from being sent.