Thomas Szabo of Mindtransplant released a script which reads a fcpxml-file in and outputs separate Nuke- and Syntheyes-files for each video that is in the Final Cut Pro X sequence. You can use it as shell-script or Automator workflow.The script has been updated to version 1.2 recently, which additionally generates a .synInfo file which is a custom file-format for importing your shots into Syntheyes. It feeds Syntheyes with all needed data for tracking a shot.

This is what Thomas wrote about the script on the Nukepedia site:

"I´m missing the "export as quicktime reference" option in FCP X. Luckily Apple introduced the XML-export feature which gave me all data I needed to "reconstruct" a video-clip in a Read node. This (bash) shell script parses a fcpxml-file and generates nuke-files for every clip in the Final Cut Pro X sequence (project). With version 1.2 the script also generates .synInfo-files, that can be imported into Syntheyes. Tested on Mac OS X 10.6.8."
 

Below are listed the features of the script and main highlights:

• No files are copied. The Read Nodes point to the same files as in FCP X.
• All in-/out-frames, sequence frame positions, clip durations stay intact
• Handle frames can be added to extend the frame range.
• Only video-files. No audio.
• Different FPS and dimensions were recognized.
• Cropping, Animations, Translations, Color Corrections, Effects and every other Final Cut related modification on a clip will be discarded!
• The generated Nuke-files are named after their FCP X name with a following "_v01"

If you want to download the script (which is available for free) click here.

Source: http://www.nukepedia.com | http://http//www.mindtransplant.com