GTX 680 x 2
HitFilm Pro (Newest Version)
Hi, I read similar topics, but they are not much to me.
So I want to ask as new.
I tracked a road with Mocha Pro plugin for Hitfilm (not Mocha Hitfilm).
It is just simple one.
During the tracking, I got the Error message “Tracking failed: couldn’t decompose drift compensation matrix”.
This happened not only this clip but also almost every clip.
This never happened with Mocha Hitfilm and Mocha Pro Standalone.
I really need your help.
Oh, I forgot to tell that I already tried to check “Disable Offscreen buffers” on and clear all caches.
Apologies if I’m making unfair assumptions about what all you have considered, but I have seen this error before when there are competing planes within the tracking selection.
Just looking at this image, it appears you have both the horizontal plane of the road and the vertical plane of the right wall in your selection. These are two conflicting planes that Mocha probably cannot square. Additionally, each blade of grass on the left is tossing out countless points of vertical tracking information that is changing with every frame. All of this information conflicts with Mocha’s ability to track the road as a singular, planar object. I’m betting this is why you are getting unreliable results and computational errors.
You might find more success using a 3D tracker, but apart from that option, I would suggest you tighten up the track boundaries to exclude everything but the road itself. Perhaps let it expand every-so-slighlty over the edges on the right where the foliage is less bushy. Just stay clear of drawing the marquee around both the bushy grass and the wall and you should get better results.
Definitely try tracking one plane at a time at least as Bh suggests, that should help a lot.
Thank you for your replies.
You said, “You might find more success using a 3D tracker”.
Do you mean After Effects 3D Camera Tracker?
I tried to track tightly one plane (one dimension).
But I have a question.
Why does it NOT happen with Mocha Hitfilm and Mocha Pro Standalone?
Even if I selected wall and grasses like below image.
Below image, it is Mocha Hitfilm.
And take a look at below image.
Sorry for the mosaic.
I tracked one plane but the same error message showed up.
Why did this happen?
Afraid I don’t have an answer about that second shot, but without seeing the motion, it’s difficult to know what all could creating a failure. That looks like a plane it shouldn’t have too much trouble with tracking.
Yes, I think the built-in 3D tracker in After Effects might track that first shot pretty well depending on how the camera moves.
What are you trying to do basically? Because in the second shot you have again taken a bigger area to track… Looking at your track layer selection, it looks like you are trying a rotoscope. If that is the case then go smaller; take one object at a time like one track layer for the tarmac, one track layer for the foot-way and so on… If or if not the rotoscope you are trying to do, I see the track layer you’ve used is very vague and ignorant with diagonal lines and miss-alignment of the track points. According to the second shot, you have a rich amount of information for you to get an excellent track. You can track all around the paint marks on the road, track the foot-ways, (individual tracks layers for each).
Also, use more track points instead of just 6 of them. This will help mocha see a better picture. Increase the min % pixel used to 90 or 95%. Use an additional track layer to exclude the moving object if any which would disturb your current track layer.
Let us hear from you after your next try.
Thank you for your reply.
I’m just testing, trying and learning how to use Mocha.
I’m a beginner.
English isn’t my first language.
So it is a little hard to learn for me.
I understood what you advised me.
Thank you again.
By the way, Could somebody tell me whether I should use lens module before tracking if I use wide lens?
I as well am having this issue all of the sudden. I have tried all the various recommendations in cleaning cache, checking the preferences, etc.
Furthermore, I am doing this on a single plane - no other competing tracking info whatsoever. It is a very straightforward track, but keeps giving me that error.
Hmm, try turning off GPU tracking or finding more texture to track on that plane, making sure there’s no shadows or reflection moving over the top of the plane.
I ended up starting a fresh AE project with the same clip - new MochaPro plugin applied to file and it tracked the same area just fine. Guess it just got corrupted originally. Thank you for the suggestions/help.