TrkMatte - effect? (AE)

[hello.ahay 0]

I'm absolutely sick to death of the TrkMatte drop down (you know the one, Luma, Luma Invert, Alpha, Alpha invert) that tracks the luma/alpha from the layer above... Is there an effect that does the same thing? ie allowing you to have just one layer in the comp that you can set multiple layers to track the luma/alpha. I've tried the various matte and channel effects but they don't track the alpha.

 

Thanks in advance.

[simonfarussell 0]

Today is your lucky day!

 

'set matte' in effects

[hello.ahay 0]

I tried that one, but when you move the layer with the set matte applied to, the matte moves with it, doesn't stay in place of the alpha layer...

 

This guy: http://www.sandervandijk.tv/after-effects-features/mattes

Edited July 26, 2016 by hello.ahay

[simonfarussell 0]

Oh well not such a lucky day!

[iMACHINE 0]

using the set Matte effect:

 

Go into the preComp where the matte object is nested, twirl open Transform and option/alt click on Position, then add this expression to it and change the values within quotes:

 

(((comp("Comp 1").layer("Deep Red Solid 1").transform.position)-(transform.position))*(-1))+(transform.position)

 

The above looks to the comp containing the layer you want to animate and takes its current position and subtracts the matte's current position from it, inverts the value and adds the result back to the matte's current position....it makes the matte move exactly the opposite direction of the layer you are animating.

 

It may help if your preComp is larger than the main comp but you will need to add some math to the expression above to make it work.

Edited July 27, 2016 by sbtread

[ianfreeze 1]

Set Matte (and Set Channel) both look at the entire comp size, not layer size. So you'd have to do some precomping to your matte layer and the layer you want to matte. Another option is the Stencil/Silhouette Alpha blend mode. Its not as versatile, but if you want to have 1 layer cut through a whole bunch, put your matte layer on the top of the layer stack and set its blend mode to "Stencil Alpha (or Stencil Luma, however your matte is set up) and it will cut down through all the layers in the comp and do its magic without having to precomp a bunch of layers.

[hello.ahay 0]

Ah, that could work. Never used the blend mode in that way. Cheers.