An evil clip that just won’t submit

Hi all. First time on the forum, long time Mocha user.

I have an 800 frame, 4k Arri CLog shot I agreed to track/solve for a client. The shot looked so ridiculously simple — a dolly push in on a woman sitting cross legged in a hallway. No camera movement, no pan, no rotation. I agreed immediately. An hour’s work at most…

I’ve uploaded a 1080 mp4 preview to Dropbox here (there’s no blanking in the original I’m trying to track):

It’s a horror/thriller movie. The goal is to be able to fill the two side walls with… whatever… spreading roots, veins, dripping blood… who knows. My brief is to deliver a perfectly tracked, corner-pinned precomp for each wall section, that can be filled with whatever the client chooses.

I’ve done this a thousand times before and saw no hazards. My first, obvious attempts were dreadful. I was surprised. I started applying the Poplin Special approach of tracking offset coplanar detail along the skirting board etc. I tried using small segments of wall texture that persist and adding to the track so Mocha is looking at multiple pieces of the wall.

I’ve tried perspective and even the “new” adjust track.
I’ve even tried a 3D camera solve. Mocha couldn’t do it.
I put it into C4D and it was much better, but still not good enough.
AE’s solve was poor quality, even after moving into rec709 and adjusting contrast/sharpness.

People, nothing is working. I have drift that won’t obey tweaking. I have jitter and swelling of the plane that shouldn’t be there. I’ve keyframed my adjust tracking as sparsely as possible.

I don’t want someone to do this for me. I’m embarrassed that it’s beating me.

What I’d really appreciate is an expert take on how I should be thinking about this track. What am I doing so wrong?

Any help greatly appreciated. Maybe Mary wants to make a YouTube weekly use case out of it? I can supply the original 4k clip as necessary.

Many thanks in advance.

Yeah, I’ll take a look. It could make a good Office Hours if we have permission to use it. Downloading now… I suspect, without seeing it, that it’s a lens warp problem or a similar texture tracking with the GPU problem but… let’s find out.

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Thanks Mary.

fyi I’m on a Mac Studio M1 Pro Max. 32gb RAM. OSX12.4 latest AE and latest Mocha Pro.
No problem with permissions for use of clip.

It is being fussy with me too. I definitely think there’s some lens warping going on that’s a problem. I’m going to really have to play with it for a minute and see what I can do. It’s a double whammy of having not a lot of really good texture and a lens curve problem and reflections on the walls and the focus. There’s a compound series of problems. I think it’s definitely doable though it’s just fussy.

I won’t deny, I’m glad it’s not just me… :grinning:

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I uploaded a 4k version to the same directory. H.264
The original ARRI clip is about 2gb.

I just spoke with the DP:

“No zoom. Fixed prime and everything moving on meticulously aligned rails”. He couldn’t remember the lens, but thinks 24mm.

OK, I will download the 4k and see if I can get anything better. I have some meetings booked out this morning, but I might have some time later to dive in.

WallNonsense.mocha (3.8 MB)

I have nothing nice to say about this shot except that it is pretty and spooky. :wink:

There’s definitely not enough texture and too many lighting and shadow occlusions for everything to just work.
There’s absolutely a slight lens curve that is making this extreme perspective wonky.
However, I got something… workable with some tweaking.

My technique:

I solved for the lens.
I made a generous holdout for the lady and all her shadows.
I did a track on the left wall using a giant shape to grab as much of the motion as I could with what texture is available.
I used translation only adjust track to nudge it into place.
I duplicated that layer and moved the surface to the opposite wall, because the right wall proved just an untrackable mess for me.
I reset the adjust track and did a new adjust track on the duplicated later for the right wall.
It will likely still need some hand tweaking in any final comp.

There you go, what a mess, I will definitely show this in Office Hours as a “what to do when it all goes absolutely wrong” shot. I hope this helps.

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Thank you so much Mary. I was able to open your Mocha project (I didn’t realize they could be saved independently…).

Thanks for putting all that effort into it. Who would have thought that a shot so seemingly straightforward could be SO problematic. Especially as you’ve shown so many difficult tracks that seemed exponentially harder.

I’m not sure tbh how to use what you’ve done, but I look forward to your Office Hours piece if you manage to find space for it. I think it will be valuable for a lot of people.

Thank you again.
And thank you for helping get over the feeling that I’m simply incompetent :slight_smile:

You can place any amount of corner pins and link them to the corrected adjust tracks when you link to the tracks. That will help you place anything you need.

You can use the insert module OR you can use corner pins and lens warping.

Office Hours for this at 1pm EST Today! Office Hours 21: When an Easy Shot Is Not So Easy [Boris FX Learn With Mary Poplin May 31th 2022] - YouTube

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