When Insert is a better choice than Remove


Quick summary : I’m into projects which require lots of Mocha Remove involvement. From time to time, I meet issues which lead me to think about using Insert instead of Remove for some reasons…

But since I’ve been doing soooo much removes, track data exports or camera solve data exports (to Fusion mainly) for so many years now, my experience in Insert is 1/10 of these other modules ones… Boooo… Moreover, even for inserts I’ve often used the track data export only and didn’t do it inside Mocha, I confess :slightly_frowning_face:

Now, after the last 60 successful remove projects, it’s high time to fix that and I have the right project to test : a guy is talking on the right side of the screen, while on the left side I have an animation to illustrate his itw (a book entering from the top and scrolling down, stops for a few sec in the middle of screen, and leaves by the left side, with fade in and out). Behind the book are flowers before a window, and other still stuffs on a table…
=> this book isn’t available in the localization the version is made for and therefore it must wipe out.

The problem : even if I have enough data - like the BG before the book appears - to do a remove, the track has to be so rock solid that the remove cannot be done without a few ghosts in the flowers. More, the cam is moving and the DOF is changing, which complicates the whole project.

I’d like to try insert instead, because the book never covers the guy, so no roto needed. But this is no logo stuff, how can I insert just the part of the image I need (around 1/3 of the HD clip, diagonal way) to cover the book animation area only ?

Hmmm ? I suppose Mary would like to see a pic ? I could later on, but if you’ve got it yet (against all odds given my sloppy explanation here :smiley:), feel free to indicate any tip or global WF…
At this point, I didn’t try inserting an image with an alpha part btw


Ok, still in progress…
Now I’ve done something the way Mary’s 2015 video showed (adding castles and clouds on a far landscape behind a lake or sea and using full image expanded surface), but my firsts steps in painting by Insert meet another issues and a few questions :

  1. I see aliasing at the edge of the cut image, even after using every technique in PS before exporting in png;
  2. When this is fixed, can I change an inserted image in the middle of the TL, or do I strictly have to insert the next image on another track ?
  3. Someone to make a quick tuto on how to correctly use the Feather tab in the insert parameters ?

THX in advance…


Problem 1 is fixed (obviously in increasing feather of the inserted boundaries in PS).
I think question 3 is just a RTFM thing, so my last focus is on question 2 above : is it correct that if I want to insert another png say in the middle of the TL, I have to insert it in another track surface ?
Or I could also ask : can I decide to change the inserted pic at a specific time by just put a keyframe and change the imported pic there ?

Because yes, some cases should be fixed by insert instead of remove and I’m really close to put an end this difficult project, but for some reason there are few areas to get a good track from and I’d like to use the good one for 2 different pics…


Hehe, I know it’s a sort of idle gossip here, but in case of someone has questions about Insert…

I can now answer myself : one must duplicate a track in order to put another potential pic elsewhere in the TL. And the feather parameters are quite basic and don’t fit in case of expanded surface.
I’m happy I found out these tiny different options now…


So removes are great for unoccluded objects with planar data moving behind them consistently, and especially if you need lighting automatically accounted for.

Inserts as a patch are better for occluded objects, objects with motion blur, and objects that need warping to look right, or anything with shadows or reflections moving over the top.

Your Mileage May Vary, but those are basic guidelines I use.



Thx Mary.
Finally, the question 2 of my second post was the most important and may deserve to be studied : say you have a 300 frames shot to be fixed with an Insert. If the project has few parts that can correctly be tracked, you may want to rely on this very track to insert a second cleanplate (say around frame 200 in this example), where the cam angle has changed… Especially because you’re happy to have this track which is the only solid one.
Here, you cannot behave as you would in the Remove tab (adding a cleanplate at a specific keyframed point), and that confused me…

At the end of the day, duplicating the track was the solution.


Sometimes duplicating the track is absolutely the solution. But you can also put a frame back in at an exact point in the insert module by using “align surface” at that frame where you need a still to match exactly. It’s not the same workflow as the remove, but the end result is the same.



Hey Mary, align surface was already the way the insert was done since the beginning (frame 1) of the clip.
I aligned surface, imported the still with the right alpha at frame 0 or 1. Then it had to be tweaked around frame (random guess, the project’s over) 212, and my own little solution was to import another plate where the content was closer to the “environment” at this very timecode.
The question is : re-doing “align surface” equals a keyframe at that point where I can import another still (different from the previous still inserted at the beginning) ?


Sometimes, if there’s a LOT of perspective, this is the best workflow. Much like needing more “cleanplates” sometimes there’s not enough information to process in the insert either. Sounds like you did the right thing for your shot.