Mask unstability : Have an issue with mask mode changing its effects on animation layer randomly

[裕大5FD8]

Hello,

I'm using After Effects CC (ver 18.4.1), and I am having troubles with my masks acting a little bit oddly.
I made two mask layers to make my animated character "pass behind" some elements of the background, and I've been doing it successfully with the "substract" mode of my mask layers. Unfortunately, without touching anything, it started to change its behaviour after some while and make my character disappear for all the lenght of the sequence and everywhere in the frame. In this bug, it would first disappear partially in unwanted places but now it's totally. The character become visible again when I change the mode of the mask layers to "none" which is not of great use.

Does someone has an idea of what is going on? I've tried touching all the modes and checked the behaviour of each elements with each other but didn't find anything weird.
I've also initially put some key animations to my mask layers to activate/deactivate it, but it didn't have any problem and then it did.
Should I delete those masks and make some new ones?

Thank you

[Ali Jaber]

Can you post a screenshot showing your workspace including timeline and comp view?

[裕大5FD8]

Sorry for the late answer!
Here it is. Is that what you needed?

(Note: I have two animated sequences (one is the character and the other is animated light effects) inside which I applied  two mask layers in the same configuration for both sequences)

While making the screenshots, I realized that if one of the mask (red) was on mode "substract" with opacity: 0%, it would make the character disappear. Yet the other one (blue) doesn't seem to have that issue.

When I make keys to make the masks "disappear" (by reducing its opacity levels to 0%) so it doesn't block future moments in the animation, the (blue) mask work very well, but the other one makes the animation disappear instead.

I put description in each image title to make it more clear. On the last one I didn4t bother to create keys for the (red) mask, it was just to show how it behaves with 0% opacity. I tried with keys before, it didn't work so I deleted it because I thought it was part of the problem.

Should I move the masks out of the frame instead of using opacity levels?

[Ali Jaber]

I wonder why you enabled 3D on the front layer, it looks like you have both layer's position at 0 in z.
Because both layers are 3D, their z position controls which one is in front

[裕大5FD8]

Because I was trying to render lights and tryed to cast shadows. It is slightly moved at -14,7 in z.
It casted shadows but I'm not sure I'll go with this result.

[Ali Jaber]

Because both layers are 3D, their z position controls which one is in front

Likes

[Ali Jaber]

Because both layers are 3D, their z position controls which one is in front

[裕大5FD8]

They both have the same position haha
So for instance if I put z in a slightly different position it wouldn't be in conflict?

[裕大5FD8]

In the screenshots I didn't enable the lights though, I thought it would be more confusing.
Actually I would eventually like to put light on the character that would stop at the object limits instead of covering the scene fully but I didn't figure out yet how to do this...
Do you think the 3D might come in as troubling the masks?

[裕大5FD8]

I changed it now
One is at -15 and the other -14, but still the (red) mask comes with trouble

[Ali Jaber]

You can work in 2D if you don't need 3D space, in this case you can split the layer at the back and put it on top when you need it in front of the tree. If you need to work in 3d animate the z space slightly for the layer on the back to move it from back to front

[裕大5FD8]

Thank you! I'll try it like this 🙂

[OussK]

when you facing unstable behavior on AE first thing try to purge the memory and the disk cache, you can do that from edit/purge/all memories and disk cache

[裕大5FD8]

Thank you, I will try it 🙂