OK, you’ve probably all beed using these for ages, but for me it’s a bit of a revelation. I’d vaguely heard of Virtual Patches from the QC 3 release-notes, but I’d never really thought about using them until recently. Now I think they’re going to be verrrry useful.
Here’s the Apple documentation for them. The basic idea is that you can drop a QTZ into
/Library/Graphics/Quartz Composer Patches
(a folder that will be familiar to Kineme plug-in users) and they’ll show up as patches in the Patch Creator. Any published in or out ports of the QTZ will appear as in or out ports in the patch when you create it in a composition. You can also add a description for the patch by adding it to the meta info for the virtual patch QTZ using the Edit Information item in the Editor menu.
To test out the system, I created a comp with just a number splitter, with a range set from 0 to 1 (which I use all the time), published in and out ports, added a description, and saved it into the correct folder. After restarting QC, it appeared in the Patch Creator panel, complete with description.
This is going to be very useful in the future, I think!
The only potential downside is that you have to save a ‘flattened’ version of any QTZ incorporating virtual patches, for portability. There’s a very good chance that I’m going to regularly forget to do this…


if only the qc gui’s implementation was actually useful!
the capability is there to have master/clone macros, within the same composition. that would speed things up no end. as it is, its a pain having to edit the virtual patch in a different editor, and then either close and reopen your comp or even quit and reload qc entirely… i can’t believe its as bad as the latter, but thats what my memory is telling me.
wow. that’s news to me. at first I thought you were talking about virtual ports… as in hooking up data types which are non-identical. this looks like it could be very useful!
Hiya toby!
Do you mean that’s something you can do already? I’m a bit confused…
It’s it’s not, I agree that it should be. QC is billed as a programming language with a visual editor, like Max/MSP. If this is the case though, it’s a pretty basic language…
I can see parallels between what you’re describing and the use of functions (or even objects in an OO language). It would be really useful to be able to do something like that in QC. I envisage grey-coloured ‘clone macros’ which can have their own settings, and can also be edited, becoming ‘real’ when their contents are altered. Maybe in QC 4.x…
a|x
Hiya Rob,
yeah, I think it’ll be handy, especially if you’re just developing your own library of QTZs on your own machine. A couple of little niggles mean I’d have to do some tidying-up before I released compositions that had been made using virtual patches, but I think it’s still going to save me time in the longrun.
a|x