ModelerMJ(Mike Jenkins) has an excellent tutorial on using his RubyTMIX to convert SketchUp models to Trainz. However, it has become outdated since we no have Sketup 15 and 16. I just downloaded SketchUp 16 and installed Mike's RubyTMIX. With it I can import into both TS12 and TANE. Here is what Mike sent to me:
I have been away from the Trainz world for quite a while due to personal reasons, and I apologize for the "lack of support" during that time. Your e-mail is a good reminder to me that I need to get "back in the game".
To your question: RubyTMIX will 'run' under SketchUp 2015, but there are issues with it looking for support files in particular places, so I need to do some work to fix this. However there is a trick you can use to get it running for now - I just tried it and it works.
1) Right-click the SketchUp 2015 icon on the desktop and select 'Open File Location'.
2) In this location (e.g. 'C:\Program Files\SketchUp\SketchUp 2015'), manually create a folder called 'Plugins' (e.g. 'C:\Program Files\SketchUp\SketchUp 2015\Plugins') and copy the RubyTMIX installation files into that folder as you usually would.
3) ALSO copy the RubyTMIX installation files into e.g. 'C:\Program Files\SketchUp\SketchUp 2015\Tools' - This is an existing folder, and it is where plugins must ne installed in 2015 in order to be recognized.
4) When you run SketchUp, you will see a new menu called 'Extensions', and you will find RubyTMIX under there.
Hope this helps. I will also make a post in the forums that describes this process.
Best Regards,
-Mike
NOTE: ALSO THAT YOU MUST PUT A COPY OF "RubyTMIX. rbs " OUTSIDE OF THE RUBYTMIX FOLDER IN BOTH THE "TOOLS" AND "PLUGINS" FOLDERS.