CC composite is great for compositing its own layer over itself again, the track mattes is good for tracking an alpha/luma of a layer above itself.
However, many times I'd like to composite, say an icon, over a circle shape - then animate each one independently (perhaps the circle scales up and the icon slides down to the centre of the circle), then, have the icon track the circles alpha channel so you only ever see the icon inside the circle.
Set matte doesnt often work as you are manipulating transform properties, and set matte seems to only work when both layers are the same dimensions or their default transform properties otherwise the matte is out of alignment.

The track matte works but you have to duplicate the circle layer and put it above the icon, then alterations to the circle animation would have to be replicated (barring fiddly pick whipping).

So, the feature would be like a track matte for any layer, essentially (could remove the track matte switch).
I think it could be a setting or check box in the "Set matte" effect, simply "track matte" which would track any layers matte/luma etc, as it appears in the composition, like it has been pre-composed but without having to pre-compose.

I hope this makes sense.

since 2018, Ae has not been updated in relation to VR/360 workflows. Ae has limited VR effects and the VR Comp Editor workflow which is also very limited and delicate script and expression heavy process.

Ae should have a spherical camera, mono and stereo. this would obsolete the stiching workflow of VR Comp Editor and it's limitations. 3d plugins like trapcode or stardust are very breakable, also all the 2d effects won't work properly without the use of 3rd party tools and even then it's very limited.

these new technologies should not be left behind, there are great things motion graphics wise you could create in Ae for 360/VR, and also for compositing video.

here are a few for the features I am looking for in Ae, please write anything else in the comments:
1. spherical camera (mono and stereo, 360 or 180) with all the perks as regular camera (depth of field, not a script to connect cameras, no stitching issues)
2. more VR effects or a native tool for integrating 2d effects for VR/360

I am not the only one who is experiencing this. In version 18.4.1 of AE when you make a comp height size 64 pixels the comp goes black. No matter what you try it goes black. I installed an older version 17.5.0 and it works fine as it should. This has wasted so much of my time on a paid job for which I had to create a comp at 960x64 and it would not let me. What is worse is your so-called Technical experts told me that some ratios were not possible which was a lie as he didn;t know what he was doing.

AE 2021 - The Layer Panel no longer displayers Motion Path handles for Effects or Motion Tracking. This is a major hindrance when animating and tweaking Effects paths or analysing Motion Tracking problems. See attached comparison from AE 2020 and AE 2021. I have also tested this in AE Beta and the problem persists.
I am trying to attach jpg examples unsuccessfully.
Here is a more detailed description:
AE 2020 >Layers panel displays >Effects motion paths with editable bezier handles; and for >Tracking Motion paths
AE 2021 Using the same settings, the >Layers panel does not display any handles for >Effects motion paths or >Tracking Motion paths
AE Beta - same as 2021

After more than a decade using AE, the sole feature that I wish was properly intergrated into the program would be ‘Blend-If’ functionality.

Blend-If is a layer style and allows the user to fade and control a layer’s alpha channel based on It’s own luminosity and/or the luminosity of layers below it.

The feature is incredibly powerful for composition and editing within photoshop and in my opinion would be a massively valuable tool for AE in the same way.

Since it is a photoshop Layer Style property it is already somewhat useable within AE, but only if you only import a PS document with the style already applied. However you now cannot change, manipulate or copy this layer style. But the fact that it is still honoured by AE and works to a very basic degree hopefully suggests that it could be programmed in easier than normal and not something that would need to be created from scratch.

Thank you very much for reading, and creating a great program!

This one is not easy to describe.
Let's say you have one layer with Particular effect (layer A). As the particles source, you have selected "Sprite", and the Sprite is a precomp, or any other source that CAN be rasterised (like an Ai file, for instance). But you chose NOT to rasterise it.
Everything works well at that stage. But later in the workflow, you create a second layer (B) with Particular, and decide to use the SAME layer (or precomp) as the source of your particles for layer A.
What happens then is the problem: After Effects chooses to rasterise your source layer, without warning, and even if this layer is locked! As a result, the appearance of your particles changes on ALL layers using this layer as a source for your particles, and good luck with that, if you don't know about the bug. It can stop you in your tracks for hours on end, if you are even lucky enough to notice what happened. It is quasi impossible to guess why the particles on layer A started to go south, especially if you set it up days earlier in the process. Anyone hit that one before?

As powerful at it may be "Set Matte" has some limitations and it is not very easy to use. More often than not you still need one layer as mask for another layer. Even simple setups become layer-salads.

My ideas to upgrade this effect:

• timepoint of layer matte should be accessable via Expressions/Keyframes. This way we can use one single precpomped Animation to mask as many layers as we want
• also 3D layers should be able to be masked by a 2D animation using "Stretch Matte to Fit"
• To use this effect I always have to precomp my footage and then "collapse transformations". There could be more intuitive ways, more resolution-independent -> like it already works with Shape Layers.