Occluded tracking

[White Lorry]
(- YouTube)

I have been trying to place a logo on the side of this truck but cannot find a technique to complete the tracking and produce stable corner pin data to use in After Effects. For a good part of the video, the truck is not fully visible. ( I believe this is referred to as occlusion ) and towards the end it goes behind the traffic lights a post and some bushes. I have tried masking these out but with no success.
The major problem is a large part of the truck moving partially out of shot.
Am I asking too much from Mocha Pro or have I simply not found the method I need to achieve this.
Any help and advice would be greatly appreciated.

OK, so, you’re not asking too much of Mocha but this IS a tricky track for a few reasons. The big reason isn’t the occlusions, it’s the slow moving light and shadow over the side of the fairly textureless container. I would try LARGE holdouts on the FG occlusions and then only track the EDGES of the container. You’ll end up with a shape like a very blocky C or a picture frame depending on your edge shape technique. You almost certainly will need to use adjust track for this shot as well. There is a lot of perspective movement and that also makes things trickier.

Can you try that and let me know? If you end up getting nowhere, email me the shot to maryp at borisfx.com and I will take a more in depth look.

Thank you for your advice.
Unfortunately I still can’t get the result I’m looking for.
I have a couple of issues:
Firstly, the tracking of the container, when occluded, becomes wildly distorted. Secondly, I cannot get the tracking to hold as the truck passes behind the traffic light and post and bushes
I think my main problem is that I don’t know what I don’t know.
Hopefully this will improve as I learn more.
I will send my project files to you via wetransfer .
I would very much appreciate it if you would take a look.
I’d really like to learn how you solve this.
Thank again.
PS If this footage is useful for a future tutorial please feel free.
It’s 3840px x 2160px 25 fps

OK, so part of the issue is the holdouts aren’t big enough. So I made them larger.

The other issue is the big blank side with not much texture, but that’s fixable with adjust track.

I think there’s some lens warping too, but I think adjust track will get us around that too.

Another major sliding issue was the very subtle lens flare across the top of the container.

I am going to send you the file back to check and see what I did. It involved a lot of selective shape placement and increasing the search area as well. Basically, trying to find the texture that’s available while avoiding slow moving occlusions and lighting changes are the key to this shot. That and adjust track.


Thank you so much for your first rate outstanding help and support.
I really appreciate your time and effort and have learned a great deal.

Happy to help!