Camera track solid keeps moving - problem with 3d camera tracker

[Khanh32674585851a]

Hi folks, first time poster here.

I’m having a hard time with my camera tracker. I attach 2 videos to elaborate the issue.

For the context, I shot the video with my iphone 11 pro, wanting to track the wall in order to attach a photo on it later.

I ran the camera tracker, it didn’t turn out well since the wall doesn’t have a lot of details (only know this after running the camera track). I end up choosing a few track points on the wall, set a ground plane, add a solid (named Reference) and camera. Put Gird effect on the Reference to see how the track doing. I had to adjust Z rotation, along with X and Y position to set the Reference solid align with the wall. But after playback, I can see the Reference solid keeps moving around.

Anyone has solution for this? I plan to reshoot the video but still wanna know about this issue. Also, can you direct me to some videos or course that properly guide me for camera tracking in After Effects. I don’t have faith on some random Silkshare or Udemy course where they choose the ideal footage to work with which is very rare in real life.

Thanks in advance.

[Rick Gerard]

There is a lot of noise on the brick wall. I would use Detailed Analysis, then first drag a selection around a bunch of trackers on the sidewalk, set an origin and ground plane, and then a solid camera from the same target to verify that you have a good track. When you have that, go to the last frame and drag a selection around most of the trackers on the wall to average out their position, create a solid, and then shift + parent a 3D graphic to the solid. Your track should be good. 

The problem with your sample video is that you have selected some points on the wall where the trackers are moving all over the place. As I scrubbed through the clip, I could see a huge percentage of them dancing around. 

Another viable option that would give you a good solid track on the wall would be to use Mocha AE and corner-pin track the wall backward from the last frame. Track everything, including perspective, then apply Corner Pin tracking to the graphic you want to add to the wall.

[Khanh32674585851a]

Thank you so much for replying to me.

I didn't know the noise would affect the quality of the track. Thank you for pointing it out.

I use camera track because I wanna project a photo on the wall later on. Is there anyway to work around with this?

[Rick Gerard]

I showed you the workaround.  Make sure that the origin and ground plane are set and accurate using the walkway. Go to the last frame and select a bunch of trackers. Add your solid to the wall. Then add a 3D layer for your photo and Shift + parent the image to the wall solid. I fine-tuned the perspective on the image of the poster using Corner Pin.

I would have used Mocha AE to do the tracking instead of the Camera Tracker because the wall provides a perfect planar surface to track. The Mocha Track is in the project. 

Here's a project file using your footage and an old image from my library.

[Khanh32674585851a]

Thank you so much. I'll try that and let you know the result. Have a great day!

[Khanh32674585851a]

I tried your approach and it worked right at the first attempt! Thank you so much! Even though I tended to reshoot the video, I wanna know more about this to avoid these issues down the road.

Also, I could not open the project file you sent. I got the error saying “The file you are attempting to open was created with after effects version 23.6 (Apple Arm 64) …” and I’m using AE 22.6.0 (build 64) on Mac M1.

Anyways, can you suggest me reliable source to learn more about camera tracking? I’ve learn the course “After Effects Compositing: 6 Tracking and Stabilization” from Mark Christiansen on Linkedin but the course’s from 2015 and I feel like it does a little for me even though I love Mark and his teaching style.

[Rick Gerard]

Here's a 22 version of the AEP