FORUMS: list search recent posts

Help with Alpha Matte and transparent text

COW Forums : Adobe After Effects

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
Justin Shewell
Help with Alpha Matte and transparent text
on Nov 16, 2018 at 8:06:57 pm
Last Edited By Justin Shewell on Nov 16, 2018 at 8:54:52 pm

I have a comp where there is text written on the screen so that it looks as if a person is writing on the screen (or the reverse side of the glass). Then I need to erase part of the text. The difficulty I am having is the transparency of the text being erased. I want to have it NOT show over the image of the eraser, but the eraser image HAS to appear BEHIND the text (because they are erasing from the opposite side of the glass). Currently, I have a solid that is parented to the eraser image (so that they move together), with a mask set as the alpha matte of a text layer with the text to be erased is white (the same as the background), which is positioned above the original text layer (text is all black).

I've attached screenshots to help explain what I have and what I am trying to do. I've attached exports (renders of single frames) and then screen captures of each frame so you can see the mask outlines as well, and the layers.

I am not sure if I am going about it the right way, so if you can suggest another way to do it, I am all ears. I am self-taught in AE, so any tutorials or explanations you can provide would be extremely helpful.










Return to posts index

Kalleheikki Kannisto
Re: Alpha Matte and transparent text
on Nov 17, 2018 at 8:38:50 am

All you need is a feathered animated mask on the text layer, hiding the text as you wipe over it.

Kalleheikki Kannisto
Senior Graphic Designer


Return to posts index

Justin Shewell
Re: Alpha Matte and transparent text
on Nov 17, 2018 at 3:39:40 pm

Would the animated mask would hide the eraser image below the text as well? I need the eraser to show, but the text to go transparent as the eraser moves across the screen.


Return to posts index


Justin Shewell
Re: Alpha Matte and transparent text
on Nov 17, 2018 at 3:57:18 pm

I figured it out. Thank you.

I put an animated mask on the layer with the white text and matched it position with the eraser image. It only worked when I set the track matte of the original text layer to be luma inverted of the white text layer.


Return to posts index

Kalleheikki Kannisto
Re: Alpha Matte and transparent text
on Nov 17, 2018 at 4:48:46 pm

If the text is black, there's no need for anything else but the hand&eraser layer and a black text layer with an animated mask. I'm not sure what you're using the white text and a track matte layers for, unless you want the text to change to white when it is front of the hand&eraser.

Kalleheikki Kannisto
Senior Graphic Designer


Return to posts index

Justin Shewell
Re: Alpha Matte and transparent text
on Nov 17, 2018 at 5:20:12 pm

With an animated mask on the black text layer, how does the text disappear? Once the eraser passes over it, it shows again because the eraser image is behind the text and on a transparent background. I was using the white layer to hide the text against a white background after the eraser passes behind it.

It is supposed to look like someone is writing on the reverse side of the screen and then erasing it, so the eraser is behind the text, not in front.


Return to posts index


Kalleheikki Kannisto
Re: Alpha Matte and transparent text
on Nov 18, 2018 at 9:55:21 am

The black text on the front layer is hidden by the mask. You just animate the mask on the text layer to cover the areas you want shown (or hidden).

Kalleheikki Kannisto
Senior Graphic Designer


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2019 CreativeCOW.net All Rights Reserved
[TOP]