04c Tracking Tips - Unlink Tracking [Mocha Essentials]

Long, panning camera shots or objects that move offscreen can seem tricky to handle. Unlink tracking is a technique that takes advantage of how Mocha works with co-planar movement, and makes these shots easy.
In this exercise we look at a sweeping, rotating shot and find a way to track any part of that wall, without any animation at all. We reinforce the idea of the separation between shape data and tracking data, taking it to its logical conclusion.
When finished, you will know one of the most useful tricks for tracking shots with longer camera moves in them, eg drone shots or long pans, dollies and tracks.
Chapter List
00:00 Start
00:26 Tracking the usual way
03:02 What is Unlink Tracking?
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#borisfx #mocha #motiontracking

[@facu_eze_peralta]

This is Gold! I love it! I didnt expect that. Love it guys! ♥

[@UmutSama]

Man, I thought that little touch was just for linking the "Layers" to each other. I was enlightened by this video.

[@borisfxlearn]

Such a powerful technique. Glad you enjoyed the video.

[@MohamedElHanoun]

U Solve my biggest problem Thanks ❤

[@danharper8749]

4:19 - "Here is where it starts to make sense"... No... Here is where everything that made sense before, goes completely off the rails.... If you aren't linked to anything, what is the tracking data being applied too, and how does it change perspective to something that isn't linked to anything? I've watched this video several times and each time get more confused.

[@borisfxlearn]

Linking in the track always refers to how the shapes move with the tracked layer. In Mocha, track data and shape data are two different things. The shape data sits on top of the track data. What this means usually is that once you track your shape, you can add keyframes to the shape independent of the track data, to get the shape fitting perfectly. Another way to use this is to link a shape to the track data of a completely different layer. This is like "parenting" in other applications. Unlink tracking is a completely different way to use this separation between the track and shape data. And a very powerful one at that. With the Link to Track set to "None", you essentially break the physical connection the shape has with the track. The shape will only move if you animate it yourself. Why is this important? Well, just because the shape isn't moving, doesn't mean that we can't create tracking data from the movement of the pixels _within_ that shape. The shape data doesn't represent the tracking data. That's the job of the Surface (discussed in Exercise 01 and 03). This means that it is easy to track long shots without having to constantly move the shape back into frame. Unlink tracking lets you use the shape as a window to track through. Turn on the Surface and you'll see that the tracking data is created even with a static shape. It isn't the easiest concept to get your head around at first. But when you do, you'll see it opens up a large number of opportunities for tracking. We do come back to this concept later in the course too, so you'll have a chance to revisit it. Hope that helps.

[@Lowkeh]

@@borisfxlearn This is an excellent answer to a great question. Thank you!

[@dipanjanghosal1662]

@@borisfxlearn oh right. Gotcha. I was thrown off by the video, but your reply cleared things up

[@AliTKhan]

This just blew my mind!!!

[@borisfxlearn]

It's a great little trick

[@augustlundby8753]

I'm having trouble. When I do this, it does the opposite of what happens in your video. I.e., the planar surface moves, but everything else remains static.

[@ronydey2696]

Great tutorial sir these is really a much helpful hi myself Rony an VFX student from India

[@borisfxlearn]

Thanks Rony, glad to hear it

[@Editson]

Genius one click magic!

[@borisfxlearn]

It really is a great technique. Thanks for the comment.

[@grantpichla]

I watched the end multiple times and read your thorough response below. Kind of stumped. Is it safe to assume that when the Shape is unlinked to the Track... then your oval stationary window (Shape) is what the program continues to look through for every frame while the brick wall viewable behind it/within that oval is shifting and rotating... so it's kind of like saying that Mocha is analyzing a new set of pixels/bricks in the wall on every new frame of tracking, as opposed to attempting to cling to the original set of bricks, which is how we're more used to working in our 'traditional' style of tracking? If so, that is really cool. But I still might have it wrong. Excited to continue watching :) Thank you for creating Mocha, and thank you for this video series.

[@borisfxlearn]

Yes. Pretty much that. Mocha looks for the movement of the planar surface as it moves through that stationary shape. If the pixels keep moving through that window in a consistent way, you get a lovely consistent track without having to chase things as they go offscreen.

[@grantpichla]

@@borisfxlearn Awesome, thank you

[@chungrongtuech4269]

cảm ơn rất rất nhiều .

[@borisfxlearn]

You are very welcome.

[@vinhdo1609]

Humm. so for what i understand. unlink track will be so powerful incase of there alot of camera movement that shape data will drift in a co-plannar with the track data. humm interesting. i will try that techniques

[@borisfxlearn]

Yes, exactly! It's really powerful on longer camera movements or tracking backgrounds.

[@eladet11]

Thanks! One thing that was different when I tried it : *minute **6:50* you turn off the visibility of the layer. When I do it, the logo disappears immediately. why is that?

[@borisfxlearn]

That was new functionality in a software update :D

[@CTZN1]

why the link layer to none, the track still drifts? :/ its a phone on the table, at first the phone is visible, then go off screen, then back on screen again. and the track is way off.

[@borisfxlearn]

Best to post this to the forums with some screenshots. forum.borisfx.com/ Unlink tracking works best when you can long camera movement. You may have better luck with offset tracking or merging separate tracks together. But join us on the forums and we can have a look.

[@tiborsalzburger1468]

Wonderful tutorial - thank you very much for this! Question: Back in AE (I'm using Mocha AE) I can see that Mocha has created some trackingdata + I can see the corner Pins following the object out of the frame on the tracked footage. BUT when I hit "apply Export" (with corner pin selected) to an null object, it creates hidden stopwatches on the null properties but no keyframes and probably no movement... Do you know why? Is there a hidden "apply shape export" button that I can only use in mocha pro or something?

[@borisfxlearn]

If the stopwatch goes on, then there must be keyframes created somewhere. I am worried that they are not being created in the correct place. Does your null object start at the first frame of the comp? Take a quick look at these next two videos. They go through the process of applying tracking data, also to a null object in one example: Transforms : kzbin.info/www/bejne/anS0dYWPhdh2ga8 Corner pins : kzbin.info/www/bejne/qZDae42bjNBqoMU

[@tiborsalzburger1468]

@@borisfxlearn Hola, thank you very much for the fast answer. I've looked into the comp an you were right with "mocha has created keyframes but not on the place where it should be." (honestly I was to lazy to look out if that could be the problem). Anyway... I had to stretch my comp out to 1 hour (before the comp was 00:00:05:00 long) and mocha has created the first keyframes somewhere on 00:00:35:00 and then has created endless keyframes. When I scretched the comp out to 2 or even 3 hours mocha has created keyframes to the end of the end of the end of the comp anyway :D Really strange. I've took all the keyframes (they were gone out of the max of 3 hours of comp lenght) and have comprimise it on the lenght of 5sec. And yeah in the end it has "worked" :D Any Idea how to not get in this "troubleshooting-workflow" again?

[@borisfxlearn]

Glad you got it working, but it is still odd. Did the original clip have any time changes or edits on it? That is very unusual. Most of the troubleshooting breaks down into one of these six things in this video : kzbin.info/www/bejne/Z6W6fJeYn7B_hKc EDIT : I forgot to emphasise the importance of precomposing too : borisfx.com/videos/quick-tip-precomp-footage-for-best-mocha-results/