'Set Matte' is delayed when moving over a .png?

[cognito art 01]

Hello,

I'm using the 'set matte' effect to create a whiteboard rubout effect of my page's content. I have 7 layers all using an inverted 'set matte' effect - using a shape layer as their source. This shape layer then transforms across the stage, giving the appearance of rubbing out the content below it.  For some reason, the .png image of a man in the screenshots below, seems to have the 'set matte' effect move across it more slowly than the rest of the screen. When I unhide the shape layer('rubout01'), you can see the green shape is totally over it, but then when I hide the shape layer('rubout01'), you can see it's not masking the man, but is masking the text.

Can someone help me understand how to remedy this. It seems to be happening with the other image too, though it's less obvious. I've attached screen shots to try and illustrate what I mean. Many thanks for any help!

[Mylenium]

Effects use layer coordinates. Of course there will be differences if your layer is not equal in size to the composition dimensions. The little guy needs to be pre-composed to a full sized comp and the effect applied to this comp-based layer.

Mylenium

[cognito art 01]

Hi Mylenium,

Thanks for the reply. Pre-composing all the elements that need rubbing out into one works perfectly. Cheers 🙂