Export tracking data to raw x-y-coordinates in mocha Pro

Dear, advanced users!
For tracking purposes only we are beginning to use mocha Pro 2.5.1.
Our setup is really simple and bases on:
Our input footage is a 4:3 picture sequence sized w 4416 x h 3312 pixel.
The tif-images are imported by choosing a framerate of 25 fps and using
the custom pixel aspect ratio 1.
A single X spline tracking layer consists of four points nearly forming a rectangle.
The tracks are done precisely by using translation, rotation & scaling calculated with large motion tracking option.
The tracks have to be exported into a simple file containing the inner point coordinates of the X spline corner points (x and y in pixels). There is no need for the edge point coordinates.
An appropriate file format was found in the Nuke Ascii (.txt)* option and we get the four tracker files containing 2 coloums with the raw x and y coordinates.
Our proof of data correctness showed a gap. The X spline rectangles point of intersection is calculated correct using simple math but the rectangles borders are 25% shorter compared to the values we estimated by marking our objects.
Is there any chance to get the the raw x-y-coordinates of the tracked data without recalculating it from the Nuke Ascii files?
We are looking forward for receiving some good ideas about it. It is not clear why Nuke, which we do not use for our purposes, gets scaled down data of the tracked planes edge points?
- Thanks so far -
cutupcloud

Dear, advanced users!

For tracking purposes only we are beginning to use mocha Pro 2.5.1.

Our setup is really simple and bases on:

Our input footage is a 4:3 picture sequence sized w 4416 x h 3312 pixel.

The tif-images are imported by choosing a framerate of 25 fps and using
the custom pixel aspect ratio 1.

A single X spline tracking layer consists of four points nearly forming a rectangle.

The tracks are done precisely by using translation, rotation & scaling calculated with large motion tracking option.

The tracks have to be exported into a simple file containing the inner point coordinates of the X spline corner points (x and y in pixels). There is no need for the edge point coordinates.

An appropriate file format was found in the Nuke Ascii (.txt)* option and we get the four tracker files containing 2 coloums with the raw x and y coordinates.

Our proof of data correctness showed a gap. The X spline rectangles point of intersection is calculated correct using simple math but the rectangles borders are 25% shorter compared to the values we estimated by marking our objects.

Is there any chance to get the the raw x-y-coordinates of the tracked data without recalculating it from the Nuke Ascii files?

We are looking forward for receiving some good ideas about it. It is not clear why Nuke, which we do not use for our purposes, gets scaled down data of the tracked planes edge points?

- Thanks so far -

cutupcloud

First of all: thank you for the fast replies and the helpful information. Obviously I did not read the Tracking Basics Documentation attentively. Today I am going to try out your suggestions and foreseeable I will succeed.
Best for you and again: Thank you for the algorithms and the extraordinary support!
cutupcloud

First of all: thank you for the fast replies and the helpful information. Obviously I did not read the Tracking Basics Documentation attentively. Today I am going to try out your suggestions and foreseeable I will succeed.

Best for you and again: Thank you for the algorithms and the extraordinary support!

cutupcloud

As Martin said, all our exports are based on the position of the surface, so you should either align this to the corners of the frame on your chosen reference frame, using the Align Surface button, or line them up with relevant features, such as the corners of a screen for a screen insertion.
Internally, we store the tracked motion as camera-space homograhies for each plane, but the only place you can find these is in our project files. If you are building a custom pipeline we could work with you to make this data available if this makes sense for both of us.
J-P

As Martin said, all our exports are based on the position of the surface, so you should either align this to the corners of the frame on your chosen reference frame, using the Align Surface button, or line them up with relevant features, such as the corners of a screen for a screen insertion.

Internally, we store the tracked motion as camera-space homograhies for each plane, but the only place you can find these is in our project files. If you are building a custom pipeline we could work with you to make this data available if this makes sense for both of us.

J-P

When you export tracking data, you are not exporting the spline points. You are exporting the surface, which is the blue square (you can turn this on via the view controls in the top bar). You will need to align the corners of this surface to the required points to get a more accurate result.
As to straight raw XY coordinates, we don’t have a format for this, although i’m sure any data you export should be easily convertable.

When you export tracking data, you are not exporting the spline points. You are exporting the surface, which is the blue square (you can turn this on via the view controls in the top bar). You will need to align the corners of this surface to the required points to get a more accurate result.

As to straight raw XY coordinates, we don’t have a format for this, although i’m sure any data you export should be easily convertable.