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Masks “stick” in place after auto-trace until their frame appears?
I’ve got a weird issue that I can’t seem to find solutions for anywhere else. Hope you might be able to help.
I’ve got a layer of my face masked so just the neck+head shows. It’s been keyed out and the threshhold effect has been applied so my head is now pure black/white. I’ve precomposed this, and what I’m trying to do is to auto-trace it to create “moving masks” of my face. These masks will have the saber effect applied to them, so my face will be recreated out of fire.
Imgur Gallery of screenshots of the issue: https://imgur.com/a/9Frx8
I’m able to auto-trace on luma no problem, but when I do, I get a number of masks appearing that are “stuck” at a frame later on in the video. See screenshots 2 and 3.
The rest of the masks in the video appear and disappear correctly, but every time I auto-trace, a few masks will just stick. I could go through and add a keyframe one frame before the stuck masks and move them out of the frame, but that would be pretty labor-intensive.
Any other ideas? Anything I’m doing wrong?
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5 Replies
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Cool idea..it is working nice…Does the sticking actually affect the render though or is it just a memory saving thing? if worse comes to worse you could seperate the masks into different layers..that might help. but also make sure to purge often
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It does affect the render, because Saber will draw any masks present. So when I’m viewing the first frame of the saber layer, I’ll see the correct mask(s) for the frame drawn, as well as like 4-5 other masks that seem to just “stick” there in place until their frame comes along (usually much much later in the video).
Separating the masks wouldn’t help, because I’d have to run saber on every layer, and it would still just “stick” until their frame comes along.
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I’m running into the same issue, with Auto-Trace leaving a lot of “old” masks freezed in place, while the PNG animation has moved on.
Did you find a workaround?
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Ah, found the culprit I guess. Saber ignores mask opacity, so while Ae is switching off masks with opacity, Saber keeps on using them. Need to manually remove these masks.
https://www.reddit.com/r/AfterEffects/comments/4acbpn/using_the_alpha_channel_for_saber/
So a fast way of handling this, would be an expression that checks if a mask’s opacity is 0, then move it off screen or something..
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SOLUTION:
Create an extra mask on Saber layer (e.g. Mask 2), but put it off screen so it’s not visible. Check on the traced mask (Mask 1) if the opacity is 0, and parent it’s position to the offscreen mask.
expression:
if (mask(“Mask 1”).maskOpacity == 0) {mask(“Mask 2”).maskPath} else {value}
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