corner pin export to after effects from mocha ae problem

[Martin Brennand]

It looks like your scale is messing up.

Go back to Mocha and tweak the surface at the point in the track where the area is the largest, then try re-exporting.

Martin Brennand | Product Manager | mocha – Imagineer Systems

[Elza Bakirova]

I did that but unfortunately it’s still the same

[Andrew Somers]

Check:

1) Are all your keyframes in After Effects on the leading edge of the frame (zoom all the way into the timeline to confirm).

2) Is your footage interpreted as 25fps EVERYWHERE ? (This problem *looks* like a possible frame rate issue, wherein some keyframes are skipped due to different frame rates.)

Andrew Somers
VFX & Title Supervisor
https://www.GeneralTitles.com

[Elza Bakirova]

Yes, all keyframes are on the leading edge of the frame
I cheked fps again, it’s 25 everywhere

Is there something else that can be a reason?

[Andrew Somers]

Can you post here the keyframe data as the file exported from Mocha?

I can’t step through the youtube video frame by frame, but is there any chance the keyframes are offset by 1 frame? Have you tried aligning them all 1 frame later or earlier?

Also, barring a solution and in view of your deadline, Red Giant corner pin has some extra features that can help manually massage such issues.

And if nothing else, keyframe the layer transform position to compensate.

Andrew Somers
VFX & Title Supervisor
https://www.GeneralTitles.com

[Elza Bakirova]

here is mocha tracking data:
12670_mochatrack.txt.zip

i haven’t tried aligning them 1 frame earlier just cause i always check twise frames that my track is starting from before i paste them to ae

i’ll try Red Giant corner pin for now, thanks

[Andrew Somers]

Hi Elza,

Based on looking at this data, I’m thinking it is possible that you made a quicktime subclip of just the section you need from the camera master or image sequence. Yes?

I’d like to draw your attention to the first two key numbers for each pin — notice they are essentially identical. meaning that frames 469 and 470 are identical (duplicates.)

Adobe After Effects 6.0 Keyframe Data

Units Per Second 25
Source Width 2048
Source Height 858
Source Pixel Aspect Ratio 1
Comp Pixel Aspect Ratio 1

Effects ADBE Corner Pin #1 ADBE Corner Pin-0001
Frame X pixels Y pixels
469 1314.17 241.406
470 1315.17 241.406
471 1317.11 241.125
472 1318.11 240.125
473 1319.93 240.065
474 1320.69 240.176

Effects ADBE Corner Pin #1 ADBE Corner Pin-0002
Frame X pixels Y pixels
469 1326.71 240.294
470 1327.71 240.294
471 1329.79 240.012
472 1330.79 239.012
473 1332.75 238.974
474 1333.64 239.068
475 1334.49 239.208

The *exact* 1 pixel X shift really just indicates that the rotospline was manually nudged between frames 0 and 1, but there is no unique mocha generated tracking data that would indicate a different frame. It is highly unlikely that Mocha would generate a perfect 1.0 pixel shift in the X axis only based on image data.

Here’s the reason I bring this all up: There is a bug in quicktime that sometimes causes the FIRST FRAME to be repeated once, IF the IN point is set to the very head of the clip.

When this occurs in Mocha, it results in the keyframes being OFF by one whole frame.

So either there is no mocha generated tracking data for the frame numbered 469, OR it is the very head of a quicktime clip and as a result that frame is repeated for 469 and 470, which will cause a one frame OFFSET when the tracking data is pulled into AE if you use frame 469 as the alignment point.

There may be another explanation for the duplicated frames at the head such as a conversion error resulting in a duplicate frame. Problems with frame rate interpretations can also lead to head frames (and other frames) being duplicated. But it all leads me to believe that the keys are currently one frame late.

That is the best explanation I can come up with given the data I have about your project. If it is not shifted keys, and you do use RG Pin, remember that Mocha has a different setting to export to RG Pin vs the regular AE Pin.

Best of luck!

Andrew Somers
VFX & Title Supervisor
https://www.GeneralTitles.com