Skip to main content
laurentk777563
laurentk777563
Participant
October 8, 2018
Answered

Motion tracker fails when parenting a frozen picture on adobe after effects CC 2018

  • October 8, 2018
  • 1 reply
  • 1007 views

followed a lot of tutorial and I think I missing something completely but I can't figure it out what... It drives me crazy.

I've a video in which I would like to paint a small part of a wall.

  • I start by duplicating my layer with my video. With the clone stamp tool, I « paint » my wall;
  • Then I freeze the picture.
  • I create then a null object, I rename it to Tracker
  • I select the back layer (not the duplicated one I turned to a frozen picture)
  • I put a motion tracker on it (rotation checked). I define the null object as a target and when I analyze it, the tracker follow well the spot I’ve chosen. I apply it then.
  • I do the parenting stuff

But this time, my frozen picture is, at first, no where to be seen and then on another, completely different spot…

I tried it a dozen of time, every way I can think of but it never work... Can somebody tell me what I'm missing ?

Any help would be really appreciated !

Thanks

This topic has been closed for replies.
Correct answer Rick Gerard

Hello,

Thank you very much for your detailed answer.

I've checked and I've the 15.1.2 version of AE (it seems to be the last available version).

I've done the painting in the painting mode and while there is indeed a whole bunch of options I didn't have access to, it doesn't change my mask situation.

I've hit the U key twice, and I've done a screenshot (actually, it's the details of my clone painting):

I recorded the issue here:

https://youtu.be/30-Qnx96Cts

I also tried doing a copy / paste instead of the painting. The issue isn't the same, but the result isn't any better...

YouTube

Many thanks for your time !

Best regards


Your mask fouls up the Clone tool because the area you are using for the source is outside the mask. That's why there is a hole in the clone.

Your motion tracking and parenting is not working because you are not returning to the same point in the timeline where you positioned the copy of the footage. The screen recording clearly shows that the patch for the wall is still in the same position as it was when you moved it into place. Move the CTI back so the patch is in the right place and then make the Null the parent.

BTW, the scale of that layer also changes as the camera move. You would get a better track if you also included scale.

I would not use either technique to repair the wall. I would use corner pin tracking using Mocha and probably generate the patch using Photoshop.

The tutorials you looked at were only fair and they did not clarify the importance of several of the steps in the process.

1 reply

R
Community Expert
Rick GerardCommunity Expert
Community Expert
October 8, 2018

What tutorial? About half of them are presented by amateurs that don't give proper explanations and a lot of them teach bad workflows.

How much experience do you have with AE and motion tracking?

Standard motion tracking requires that you select a sufficient amount of detail, verify that the track is good by watching the trackers as you scrub through the footage, applying the track to something like a solid or a null so you can verify the track is good, then attaching whatever you want to attach to the track through parenting. It sounds like you are missing critical steps.

I don't completely understand your explanation. How are you using the clone tool? Are you familiar with the tool? If this were my project and I wanted to use the clone tool to remove something from the wall and the camera was moving and the perspective did not change I would probably pick a good frame to fix, export that frame as a still image, do the painting and masking in Photoshop, then import the frame and lock it to the wall using motion tracking. If the perspective changed cloning would involve an entirely different process. If there was something moving in the frame that I needed to clone over and the lighting changed, that would involve a completely different process also.

What do you mean when you say Freeze the picture? Are you using Layer>Time>Freeze Frame to do that?

What do you mean do the parenting stuff?

Did you move the CTI to the right spot when you parented the fixed frame to the tracker? That is a common error.

laurentk777563
laurentk777563Author
Participant
October 9, 2018

Hello Rick, thank you for your answer.

I follow particularly this tutorial (the guys seems to know his subject...):

Answer to Question for After Effects: How to remove unwanted objects from a moving shot. - YouTube

and this one:

After Effects Tutorial - How To Remove Anything From Your Shot - YouTube

Amongst the problems that occurred, this one (see the video below):

capture01 - YouTube

I've painted the wall with the clone stamp tool, but when I try to put a mask on it my painting disappear...

Here, in this second video, I copy past an area of the wall on the spot I would like to change, but it doesn't work at all (despite the motion tracking which seems to work well):

YouTube

Thank you for your help.

R
Community Expert
Rick GerardCommunity Expert
Community Expert
October 9, 2018

Regarding your masking problem, there are two obvious things that I see. First masking is not necessary at all if you choose Paint On Transparent. When you paint you should be in the Paint workspace. It will give you more options. One of the options is Paint on Transparent. You can turn that on or off. As long as the original and copy layers are lined up you can select the Paint on Transparent option in the timeline and then switch the source to the original layer. No masking required. In this screenshot I have just started to paint out the logo. After painting the first stroke I turned on Paint on Transparent and selected the Original layer as the source:

You can also use the mask tools at the bottom left corner of the Layer Panel. This will help you see what you are doing. You just have to select the original layer as the source before you start painting:

You will find a lot more useful information about the Paint tool if you look at the help files and community resources by typing Paint in the Search Help field in the top right corner of After Effects:

I'm not exactly why your mask appears to be hiding the paint effect. It could be that your version of AE is not up to date. I'd check on that first. Second, you didn't show the modified properties of your layer. You do that by pressing the U key twice (English Keyboards) or twirling down everything in the timeline. I also don't know what on the layer below because you never turned off the top layer or soloed the bottom layer. If you check the mask in the layer Panel what do you see? What are the mask settings?

Your motion tracking problem is a common mistake. Look what panel you are using when you do the parenting and check the time:

You should be looking at the Composition, not the layer, and the time when you attach the fixed layer to the null is when the replacement is in the right position.

Both of these tutorials are just fair. The first tutorial, the western scene, used a pretty inefficient way to do the repairs to the scene. There are much better and faster techniques for doing almost all of the repairs to that shot and the result would have been cleaner with a lot less work. He got the job done and explained things fairly well, but he left out a few things in the explanation that probably would have made your life easier.

The second tutorial was also only fair. The technique was ok, but things were left out of the explanation that caused you to miss a few things.

I hope this helps you a bit. If you can't figure out why the mask you drew didn't work as planned please post a screenshot (Shift + Ctrl/Cmnd + 3) of the layers with all modified properties revealed by just dragging from the desktop to the reply field on the forum.

Terms & ConditionsAccessibility statement
Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices