Activity › Forums › Adobe After Effects › White intersections in mask
-
White intersections in mask
Posted by Scott Petterson on December 19, 2018 at 11:26 pmHello,
I encounter a problem with “white areas” appearing when a mask overlap itself.
I’m making a “whiteboard style” animation following this tutorial:
https://www.oakcomputing.com/how-to-use-adobe-after-effects-to-animate-a-sketch-from-illustrator/comment-page-1/#comment-288205I copy a drawing from Illustrator and paste it as masks into After Effects.
Several masks are then created (one for each stroke in Illustrator).
I do make sure that all of the masks are set to “Add” to avoid that intersections between the masks appear as white
– but “white intersections” still appear when an individual stroke (and a single mask) overlaps itself
It looks like this:

Hope someone can help me out, that would be deeply appreciated, thank you in advance!
Scott Petterson replied 7 years, 7 months ago 3 Members · 10 Replies -
10 Replies
-
Max Haller
December 20, 2018 at 6:37 pmNot totally sure, but off the top of my head try rearranging the order of the masks in the layer. See if that makes a difference
-
Scott Petterson
December 21, 2018 at 3:13 pmThank you for your reply.
It appears, however, when a mask overlaps itself – so it also happens when I only copy 1 stroke from Illustrator and thereby only create 1 mask when I copy/paste it to After Effects.
I just made a stroke in Illustrator and copy/pasted it as a mask into AE – here’s the result:

Any clues?
-
Kalleheikki Kannisto
December 21, 2018 at 5:03 pmLooks like the problem is the path itself in Illustrator. It shouldn’t have those extra triangular loops. Need to expand the shape in Illustrator and edit them out.
Kalleheikki Kannisto
Senior Graphic Designer -
Scott Petterson
December 21, 2018 at 8:52 pmThank you for your comment, Kalleheikki Kannisto.
The stroke looks fine in illustrator both when it’s a path and when I expand it.
It’s how the masks work in AE: if you keep Illustrator out of the equation, and just go directly to AE and make a mask, the mask will be inverted in any area where the mask overlaps itself.
Hm :-\ Maybe it just not possible to set AE to not invert overlapping areas. It surprises me, that this is not a very commonly discussed issue, if the tutorial I’m following is a common way to make animated strokes…
-
Kalleheikki Kannisto
December 22, 2018 at 7:27 am[Scott Petterson] “It’s how the masks work in AE: if you keep Illustrator out of the equation, and just go directly to AE and make a mask, the mask will be inverted in any area where the mask overlaps itself. “
That’s correct, which is why you need to to edit them out in Illustrator to have no such overlaps before copy-pasting into AE. Pathfinder operations come in handy there.
Kalleheikki Kannisto
Senior Graphic Designer -
Scott Petterson
December 22, 2018 at 1:03 pmI see – if there’s a quick way to do that in Illustrator it would be very handy! But if I manually need to edit these areas in illustrator, it wouldn’t make sense to use this method for me, since I need to do it for many drawings.
I will do some research on Pathfinding operations. If you know how to quickly accomplish what I’m looking for or know of a good tutorial about it, I’d much like to know – thank you.
-
Kalleheikki Kannisto
December 22, 2018 at 3:22 pm -
Scott Petterson
December 23, 2018 at 1:47 amKalleheikki Kannisto:
THANK YOU!1 ton of gratitude for you.
It works for me and all is good. There is one small detail that I plan to work my way around by keeping the issue in mind when making the drawings – but I’ll just show it here in case you have another trick up your sleeve:
When I animate the stroke, I will reveal parts of ‘the rest of the stroke’ that should actually not show up yet (see img#3 here):




Have a very good day, Sir.
-
Kalleheikki Kannisto
December 23, 2018 at 7:04 amProbably the simplest way, if you have a lot of these, would be to split the shape in two in the middle of the loop part, so it is really two separate animations and animate one part right after the other to make it seem continuous.
The other way (one I usually use, since I don’t encounter this issue that often) is to add an animated mask which hides those parts of the second half of the line that do not need to show up when it is first crossed. More fiddly, but easy enough if you have just a couple of them to deal with.
Kalleheikki Kannisto
Senior Graphic Designer
Reply to this Discussion! Login or Sign Up
