Where does After Effect seem to fail?


Is Mocha very different from the 2D tracker in AE? Because the 2D tracker totally fails. Even if I can easily follow a point, the movement of the retouching is completely wrong (certainly because the perspective changes in the pan). With this shot I have now done it in such a way (however, this is not the one that is actually about in the thread, but the one with the not perfectly moving plane) that I make a corrective movement with another zero object. Still not perfect, but enough in that case. I can't invest any more time in that anyway.



Yes, AE's 2D trackers are punt trackers. Just hold a point, or 4 points for a corner pin. They can often fail, or one of the 4 points for a corner pin is not always visible and as soon as one is missing - puff pie with the track and manual work.

A PlanarTrack like in Mocha, for example, is something completely different. You use a mask to define which pixel area should be tracked. All pixels in this area are tracked, partially obscuring objects are ignored (and can be masked out). The PlanarTrack creates a pseudo-3D plane based on pixel movement because, as the word planar suggests, all the pixels you track should be approximately on one plane, and the planar track assumes they do, and a "best fit" 3D plane spans whose change in perspective corresponds to the overall change in the pixel area. You can use this track in AE, for example, as a corner pin (the 4 points correspond to the virtual 3d plane from Mocha). For example, ideal for flat things such as walls, signs, advertising banners, etc. However, you can also track everything else in a planar manner, mainly, as in Mocha, it is used for rotoscoping.

Of course, you won't always reach your goal. Which track is necessary when, depends on a lot of factors in the shot and what exactly needs to be done.


Unfortunately not - and in principle that's exactly the problem (now it's about the shot of the original question again). If it were really just scaling, it would really be done in three seconds. But which position should I hire? Because immediately after clicking the 3D button, the level jumps. And last but not least, due to the changed alignment that I take over from the camera, it is quite a fiddly job to get the position AND the scaling exactly at the same time.



I thought you had already explained that to yourself by taking over the position, I then added the rotation and the movement along Z to that in my explanation.

Described again step by step.

You have a 3D plane, this is at the origin of the coordinates. You've got a camera. At frame 100 you want the plane to be centered in front of the camera in the size of the frame:

To do this, do the following:

1. You copy the position of the camera at frame 100 onto the layer.

2. You copy the rotation of the camera at frame 100 onto the plane.


Your plane is now on the position of the camera and its orientation is identical to that of the camera. Since it is "on" the camera position, you cannot see it. So you push her away from the camera. To do this, do the following:

3. You choose your plane in the top view, or another perspective, and move it forward along its Z-axis. The blue handle (when axis tapping is active, you will see a small Z next to the cursor, you have to hit the arrow in the middle ...). Your anchor point thus remains in the center of the image, since the Z-axis of the plane is the visual axis of the camera due to the adopted rotation. Since the plane is in the middle of the frame, you only need to scale it, and as I have already described, its position along Z does not matter when you just pan, so just move it away from the camera until it almost fills the screen and then just scale it up until it fills the frame exactly.

By the way, as a general explanation again: Your level does not jump. In After Effects, layers are by default at the origin of the coordinates. It may be that your camera happens to be looking exactly at frame 1, but this is not always the case depending on what the 3d solver thinks is right. Then stop at frame 100. What you've tracked is the camera, and it just moves / rotates. A 3d plane in a 3d room is something completely different from a 2D plane.

With the above steps you have achieved what you want on frame 100. But whether the plane stays in its correct position or drifts on the frames before or after it really depends on whether it is a pure pan. If it is a pure pan, it will stay in its right place from frame 1 to the end and not drift as long as the camera track is correct. But if it's not just a pan, your track is not precise enough and it will drift. The same applies if the camera has translation values, since this level along the camera depth at frame 100 does not correspond to the actually existing 3D object on which you want to project your retouching patch.

But your level to where you want it to be (centered and filling the screen) you get it as described above.

I can actually only tell you if there is a problem in other parts of your recording if you could see the shot.

I hope the explanation is now understandable - if not, just contact me again, then I will have to paint something or screen capture

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Small edit that may be enough for you for now and leads you to your goal faster than doing it "by hand" (your level must have a scale of 100% otherwise it will be too small or large in the picture):

Select your 3d layer, then Layer-> Transform-> Center in View. Your camera view must be active.

This means that the plane is also centered and correctly scaled in the view, but its alignment is not yet.

Then you can just take over the rotation of the camera. Either by copy & paste (recommended) or as follows, but the method fails quite quickly and degenerates into more work, but for the sake of completeness:

For this you could choose Layer-> Transform-> Automatic alignment ... "Align to camera". Then it is correctly oriented. Then you have to go into the dialog again and set the auto-alignment to "None" so that it no longer automatically aligns itself to the camera. Actually it should stay as oriented as it is ... but it doesn't, you have to complain to Adobe. However, you can then duplicate them, set the alignment to None for the duplicate, and then get the two levels coincident by rotating the unaligned ones. However, the alignment fails at certain angles, so please enjoy with caution and possibly do it by hand. Especially since matching rotations is much more fiddly than scale ...

In the end, this does the same as copying rotation and position, moving and scaling.