Fixing the Magic Mask bug?

So the questions is, when you've used a bajillion magic masks throughout the film, how do you narrow it down to which one is causing the problem?
https://forum.blackmagicdesign.com/
https://forum.blackmagicdesign.com/viewtopic.php?f=21&t=222924
Sam Steti wrote:Hey
It's funny I've been torturing MM options for 10 days now, and a lot of questions rise (also I'm asked a lot about that good old cache loss at relaunch).
I won't bother you with my analysis, but what I can reckon that in order to prevent almost any issue, you may want to either export the matte, or render in place when you think everything about the matte itself is ok.
Sam Steti wrote:
TBH, I'm aware that exporting 200 mattes won't make it, especially when you know it's just a security step one shouldn't have to do. I just write it because in case of you're into large comps, re-importing mattes also has a lot of other benefits.
Consequently, rendering in place not only ensures you'll find exactly what you've previously done, but also allows you to go back to the track step if needed, so it's just an armor locking your work for the time you need. Even changing resolutions shouldn't have any impact on what's rendered in place.
Marc Wielage wrote:Well, you could check the Magic Mask Tracking window on each clip and make sure the tracking lines start on the first frame and end on the last frame. You can sort the Clips shown in the thumbnails window by "Tracked," and I think they should come up that way.
Marc Wielage wrote:I've cautioned students, "don't arbitrarily spend lots of time masking people with Magic Mask. There's always another way to do it in Resolve, and it might be a lot faster and more direct doing it one of those ways." I'm just finishing up a feature tonight, and I'm guessing I have about 250-300 tracking masks all done with Power Windows, frequently PowerCurve windows. The advantage is you can count on the tracking to never fail, even if the actor walks out of frame, or somebody walks in front of them, or the perspective of the shot changes radically, like a dolly out a window.
Granted, there are occasions where Magic Mask is not only the right tool to use, it's the perfect tool to use. But I try to mull it over and make sure there's no other way that might be 80% as effective and get done in 10% of the time. When I do use a Magic Mask, I almost never have a problem, unless I change resolutions and it has to re-track, something like that.
Sam Steti wrote:Hey
...render in place when you think everything about the matte itself is ok.
Marc Wielage wrote:Well, you could check the Magic Mask Tracking window on each clip and make sure the tracking lines start on the first frame and end on the last frame. You can sort the Clips shown in the thumbnails window by "Tracked," and I think they should come up that way.
I've cautioned students, "don't arbitrarily spend lots of time masking people with Magic Mask. There's always another way to do it in Resolve, and it might be a lot faster and more direct doing it one of those ways." I'm just finishing up a feature tonight, and I'm guessing I have about 250-300 tracking masks all done with Power Windows, frequently PowerCurve windows. The advantage is you can count on the tracking to never fail, even if the actor walks out of frame, or somebody walks in front of them, or the perspective of the shot changes radically, like a dolly out a window.
Granted, there are occasions where Magic Mask is not only the right tool to use, it's the perfect tool to use. But I try to mull it over and make sure there's no other way that might be 80% as effective and get done in 10% of the time. When I do use a Magic Mask, I almost never have a problem, unless I change resolutions and it has to re-track, something like that.