Output files question

Hello Mocha experts,

I’m conducting a research that involves tracking objects from simple videos, and for this purpose I need to use the information in the Mocha output files, instead of exporting them back to AE for further work as most people seem to do. Unfortunately i don’t understand the output files entirely.

  1. In the After Effects Corner Pin (corner pin only…) output, do the pins represent the minimum bounding quadrilateral of the tracker shape in every frame?

  2. In The After Effects Transform Data (anchor point…) output, the anchor coordinates seem to be of the centroid of the said quadrangle, is this the case?

  3. Unlike the coordinates in the two previous output files, the Mocha Shape Data for AE output doesn’t use pixel coordinates for vertex location, but decimals that i can’t understand. I’m referring to the line that appears in the output file for every keyframe in which the shape was transformed. What do these numbers stand for? For example:
    0 XSpline(Point(0.678861,0.469971,0,0.5,0.25)Point(0.684263,0.469021,0,0.5,0.25)Point(0.686935,0.463006,0,0.5,0.25)Point(0.688538,0.456673,0,0.5,0.25)Point(0.688775,0.452241,0,0.5,0.25)Point(0.6864,0.448019,0,0.5,0.25)Point(0.684441,0.447281,0,0.5,0.25)Point(0.681533,0.446753,0,0.5,0.25)Point(0.678089,0.445275,0,0.5,0.25)Point(0.675359,0.444431,0,0.5,0.25)Point(0.673221,0.447914,0,0.5,0.25)Point(0.671856,0.453296,0,0.5,0.25)Point(0.671144,0.459312,0,0.5,0.25)Point(0.672747,0.46575,0,0.5,0.25)Point(0.675418,0.468177,0,0.5,0.25))

Thank you very much

Do you only have access to mocha AE? The mocha AE data export is not going to be the best export for this kind of information. But if you want to try a trial of mocha Pro, the Silhouette or Nuke ASCII output might have better data for you.

Thank you for replying this quickly.

At the moment I do because the initial idea was to use AE for tracking until Mocha was discovered. I’ll read about what you have suggested and perhaps get the trial.

Regarding my questions, I understand the third one is hard to answer, but do you know what the corner pins represent? What are they in relation to the shape?

Again, thanks

Ah, I didn’t answer all three because I truly didn’t think the AE output was going to help you so much as the other outputs I mentioned.

The corner pin exports coordinate data for all four corners of the surface tool in mocha.

The transform data is the center of the surface tool in mocha, so yes, you are correct.

The shape data is something specific to the AE export so that we can convert our data into something after effects understands. I would have to consult with my dev team to know more about that, and it’s probably better to answer that question in email. maryp@imagineersystems.com

Well, the conversion of shape data to pixel coordinates seems like a black box I would rather stay away from.

Regarding the Silhouette or Nuke ASCII outputs that Mocha Pro provides, what are they exactly?

They’re coordinate systems for corner pins. Either way you’re going to have to do some coding to get the data into a nice and neat format.

In mocha Pro we have the ability to read the motion of the surface or the spline points using Python.
This might be better suited to your research: Boris FX | Documentation

The python functionality however is not available in mocha AE.

Thank you both, this Python functionality indeed sounds interesting.