Hi,

I’m having trouble controlling a Virtual Set from Bitfocus Companion, even though everything works fine locally inside vMix.

Setup

vMix on Windows 11

Bitfocus Companion (vMix module over TCP is working: I can control layers, tally, etc.)

I’m using a custom Virtual Set with a config like this:

<virtualSet>
<input name="Background" x="0" y="0" zoomX="1" zoomY="1" rotateX="0" rotateY="0" rotateZ="0" dynamic="True" />
<input name="Layer1" x="-0.667" y="0.667" zoomX="0.33325" zoomY="0.33325" rotateX="0" rotateY="0" rotateZ="0" dynamic="True" />
...
<input name="Layer9" x="0.667" y="-0.667" zoomX="0.33325" zoomY="0.33325" rotateX="0" rotateY="0" rotateZ="0" dynamic="True" />

<!-- 4 zoom presets -->
<zoom name="1" x="0" y="0" zoomX="1" zoomY="1" />
<zoom name="2" x="0" y="0" zoomX="3" zoomY="3" />
<zoom name="3" x="2" y="-2" zoomX="3" zoomY="3" />
<zoom name="4" x="-2" y="-2" zoomX="3" zoomY="3" />
</virtualSet>


In vMix, this input shows up as Virtual, with a name like 277 CV X1.[ID] [Name]

What works

In Settings → Shortcuts, if I create a shortcut:

Function: SelectIndex

Input: 277 CV X1

Virtual Set Zoom / Value: 1 (or 2, 3, 4)

then pressing the assigned keyboard key correctly changes the zoom preset of the Virtual Set.
So SelectIndex is definitely working in vMix for this input.

What doesn’t work

From Companion, I cannot get this same SelectIndex to trigger via TCP.

The vMix module is connected (I already control other things like layers, tally, etc.).

Using the action “vMix: Scripting – Run custom command”, I tried several commands, for example:

SelectIndex&Input=277&Value=1

SelectIndex&Input="CV X1"&Value=1

and a few similar variations.

None of these attempts change the Virtual Set at all, while the internal vMix keyboard shortcuts do.

I can work around this by using vMix shortcuts plus the Companion “Shortcut – Press” action, but I’d really like to understand the proper way to send SelectIndex to a Virtual Set via the TCP FUNCTION API.

My questions

What is the exact syntax to call SelectIndex on a Virtual Set via the TCP FUNCTION command?
(e.g. FUNCTION ??? Input=??? Value=???)

Are there any special considerations when using custom Virtual Sets (created from config.xml) compared to the built-in ones?

Are there any known limitations related to input numbers (e.g. over 300) when using SelectIndex through the API?

Thanks a lot for any help, and I can provide screenshots or the full config.xml if needed.

Cat