Loading Markers from Blender Does Not Align Correctly

[Maya MatchMove Solver]

Hello,

I had a question from someone joining the mailing list, I figure it's best to answer here in case other people have this question:

> I was tryin to use your tool to solve a rotoanim shot using blender but I can´t get the image plane on maya aligns correctly to the 2d tracker from blender, Is there a tutorial for that?

I don't have any video tutorial for Blender and mmSolver, however I have some steps written here:

https://david-cattermole.github.io/mayaMatchMoveSolver/tools_createnode.html#copy-2d-tracks-from-blender

Blender has some limitations unfortunately.

Firstly, you should track an undistorted image sequence in Blender because Blender doesn't provide a function to undistort 2D tracks, so I cannot provide that features. Therefore when loading Markers from Blender make sure you choose "Distorted" from the window.

Second, make sure that the "Use Embedded Overscan" checkbox is disabled in the Load Markers window. The "Use Embedded Overscan" feature is designed to automatically calculate the correct scale for the markers assuming the camera field of view (film back and focal length) are consistent in both applications. Unfortunately Blender doesn't allow animated focal lengths for cameras in the Motion Editor, therefore mmSolver cannot accurately support such a feature.

Have you tried those workarounds? If so, can you provide more detail to what you are doing, and how the markers are not matching? Preferably screenshots would be great too (if you're allowed to share screenshots).

Thanks,

David

[Salvador Almanza]

Hey David! Thanks for the quick response!

I've tried those workarounds but didn not get to make it work.

The thing is that the image plane doesn't load properly into the Maya's camera and when I import the image plane/sequence into the camera inside Maya this is happening:

As you can see, the points are there in the position and if you scrub in the timeline they move perfectly BUT they are not in the right place on the girls black dots..

I have no way to remove the distortion of the plate (hollywood camera work as you can se) and I want to try it first before using it into the real thing cause I want to implement  this for rotomation shots at the studio I work at and they dont use 3Dequalizer to track but PFTrack and as far I as know PFtrack exports txt files from 2d trackers but what  I dont know is that the  PF txt format is the same as 3DEqualizer and if the tool supports loading a txt file instead the UV one.

So, Blender looked to me the best option to try.

Hope you can help me to solve this.

Thanks again for the response and thanks for creating this amazing tool

If I can help with something in return, just let me know.

Best regards!

S.

[David Cattermole]

Hello Salvador,

Sorry for the delay, your email was sent to my Spam folder and I just found it now.

I think the issue you are having might be caused because the Camera Film Aperture is not the correct aspect ratio as the image plane.

For example, in the screenshot your has a Camera Film Aperture of 1.417 x 0.945 inches (36.0 x 24.0 mm), but the Hollywood Camera Work footage you are using has a final 16:9 aspect ratio (because the format is 1280x1080 HDV with a 1.5 Pixel Aspect Ratio, based on the website).

In the screenshot the Markers appear to be vertically mis-aligned only, which could be caused by the misalignment of the aspect ratios between the Camera and the Image Plane.

I would recommend changing the camera to the correct aspect ratio. Change the Camera Film Aperture to 1.417 x 0.79724 inches (or 36.0 x 20.25mm). If that doesn't fix the problem, try deleting the Markers and the Marker Group, changing the camera Film Aperture, and then using Load Markers again.

Regarding PFTrack 2D Tracking support, I would recommend either using Tracksperanto to convert the "PFTrack/PFMatchit .2dt file" format to "3DE v4 Point Export file" format, or if your studio has someone that knows how to write Python code, they might be able to write a script for PFTrack to support the mmSolver .uv format. Tell them to get in touch with me, preferably via the GitHub Issues page where we can discuss any problems. Ideally if your studio writes such a script, I'd love for it to be included in mmSolver so that it makes everyone's life easier when using PFTrack/PFMatchit.

https://tracksperanto.guerilla-di.org/

If your studio is behind a firewall, then you might be able to install Tracksperanto as an internal tool:

https://github.com/guerilla-di/tracksperanto

David

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David Cattermole

[David Cattermole]

Hello again,

I should explain why I suggested to use 3DEqualizer v4 .txt file format. It is because mmSolver currently supports 2D Markers to be loaded in any of 3 formats:

- mmSolver .uv file (custom format with extra features)

- 3DEqualizer4 .txt file format (but the user must enter the image resolution)

- Autodesk MatchMover .rz2 file format (but the software is now unsupported and cannot be downloaded anymore).

Another way forward with your PFTrack 2D tracking points file is if I can support importing the files that PFTrack natively exports.

If you can track a few points in PFTrack with one of the Hollywood Camera Work image sequences and then export and send me the exported 2D tracking files, I can perhaps write an importer for mmSolver so it can natively load the PFTrack files.

If you do want to do that, can you please also send me a PFTrack file with 4 2D trackers. Each 2ad tracking point should be placed exactly on the corners of the image, at the lower-left, upper-left, upper-right and lower right corner, and these points should be named after the corner that each point is in.

With these two files I can write an importer for PFTrack without having PFTrack installed at all.

David 

[David Cattermole]

Hello everyone,

As discussed with Salvador, I will provide an importer for PFTrack 2D Tracks. You can track the progress here:

https://github.com/david-cattermole/mayaMatchMoveSolver/issues/239

I plan to release this feature in a v0.3.16 release which will also include support for Maya 2022 (backported from the latest v0.4.0 alpha).

https://github.com/david-cattermole/mayaMatchMoveSolver/milestone/21

David

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David Cattermole

[David Cattermole]

Hey everyone,

This feature is now released in v0.3.16:

https://github.com/david-cattermole/mayaMatchMoveSolver/releases/tag/v0.3.16

Check out the Load Marker documentation for more details:

https://david-cattermole.github.io/mayaMatchMoveSolver/tools_createnode.html#load-markers

... however, basically you just need to type in the resolution of the plate that was tracked in PFTrack.

PFTrack supports both ".2dt" (PFTrack 4 and 5) and ".txt" ("node based" PFTrack) file extensions which makes things slightly confusing since 3DEqualizer also uses ".txt". The Load Markers tool will now automatically detect the correct format.

Naturally, since the PFTrack format doesn't support any "fancy" features, like the ".uv" format does, don't expect any "overscan", or distortion/undistortion features to work.

David

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David Cattermole