Allow Track Mattes to "Stack"

[hellopaul4]

If I'm using "Matte Layer 1" as a Track Matte for "Fill Layer 3", and then apply a Track Matte to "Matte Layer 1", it has no effect. Her's an example...I want to isolate the thumb:

If I set the "Hand" layer's track matte to layer 2, I get this...all good so far:

...now I want to isolate that thumb, so I set Layer 2 (the hand matte) to use Layer 1 (the rough thumb matte) as a track matte:

...not the desired result. Obviously I Layer 2 should use the matte of Layer 1, but it doesn't.

[Shebbe]

Maybe in your case an undesired result, but I don't think this is a bug. Track matting layers only consider the referenced layer itself. Not other references further down the line. You could work around this in two ways. 

1. Using masks on the source rather than separate shape layers, with hand mask on add, then the thumb mask on intersect.

2. Putting a set matte effect on the source that references the hand layer, then track matte the thumb layer.

[hellopaul4]

Yes, those are the workarounds I've been using, but it really does seem like a bug rather than "as-designed".

We all know the limitations with the Set Matte effect, and how it rarely produces useable results if the layer sizes differ, so pre-comping Set Matte's target layer is often the only feasible method, and pre-comping just creates more clutter in the project. It'd be great if we had an option in "Set Matte" to "don't be stupid and just behave exactly like a Track Matte" (or maybe a brand new Track Matte effect, that behaves exactly like the existing Track Matte, but would allow stacking of track mattes? <<< UPVOTE THIS please!).

[Shebbe]

It can only be a bug if you explicitly know that it was supposed to behave in a different way prior to this which it doesn't afaik. But I understand why you desire it as it can be more practical as default behavior. In that case it would be better to post an idea on the main After Effects board instead of a bug on the beta.

[JohnColombo]

Thanks for calling this out, @hellopaul4. @Shebbe is correct—the current behavior is as designed given the current architecture of the underlying After Effects render graph. Stacking the mattes would be considered a new feature or enhancement, so I've moved this thread to the AE Ideas section and updated the title for clarity. (Feel free to choose a different title if you disagree with my edit to the title).

Thanks again,

- John, After Effects Engineering Team 

[JohnColombo]

This functionality has come up in conversations I've had with @Brian C Carter. We'd love to hear more of your thoughts about how this could work beyond the obvious stacking case, if it would need other UI, etc.

[hellopaul4]

I think the whole thing could be solved if we had the option, in the Set Matte effect, to specify "post-transform": Maybe in the layer selection details pop-up menu, as well as "Source, Masks, Effects & Masks" we could also have "Effects, Masks & Transforms" which would make it work EXACTLY like pick-whipping a Track Matte. Or just a "Track Matte Behaviour" checkbox if changing that menu - which is common to all layer selections - would create too many problems.

[SebbieJ]

This would be so useful! I'm always having to add track mattes then separate set matte effects to try and get the same effect.

[Sterphy]

AE desperately needs to take a leaf out of most other composting and animation apps and bring in some kind of nodal workflow.  I like using layers, but it would be great if we could treat each layer and comp like a node - it wouldn't have to be too disimilar from the parent & link box on the side.  Then we could connect various layers to one object to combine it and then use that as a matte, or adjustment layer. Too often the answer is to precomp it, but in most cases precomps absolutely SUCK!  They break too many effects, they slow down your workflow because you have to keep coming in and out of the precomp and they're just too limited. Tbh, what I think a lot of us would like to see is Adobe stop releasing new versions every year, because it's just frustratinng looking to see what has stopped working this time, and put resources into releasing a reworked app with cool new features that work. 

[hellopaul4]

You mean something like this?

I remember ye olden dayes when the Flowchart was introduced I thought we might be getting something akin to a node-based workflow, but almost a quarter of a century later, it has received very little love. Wouldn't it be nice if Adobe changed their mind on this? (I did have a brief conversation with Adobe a decade or so ago about whether we might be seeing something a bit "nodey", and the answer was a firm "no").

I used Nuke for the first time a couple of weeks ago for some complex tracking, and when I hopped back to AE, I really missed the ability to link "this thing to that thing". (Obviously the pick-whippable Track Matte is lovely, as are expressions, but I did very much like Nuke's nodes!)

[Shebbe]

Yea full nodes as an alternative way to set up your compositions would be the ultimate goal for compositors. This would require very careful considerations on how this would operate in an ecosystem based on layers and timelines. I would love it but I also think that there is still a lot of unused potential for layerbased functionality.

[Sterphy]

Yeah something like that, and there's definitely ways to do it.  I know there's a plugin that can bring nodes into AE, but my only issue with 3rd party plugins that bring a whole new workflow is you don't know what Adobe is going to break when they release the next version in 5 minutes' time.  For me though AE just "feels" a bit outdated - I used to love it annd thought it was incredible when I first used it nearly 15 years ago, but it hasn't innovated really in the whole time I've been using it, and the only advances are being made by third party devs... which isn't good enough imo