You may find information on this in:
"Automatic SketchUp - Creating 3-D Models in Ruby"
by Mathew Scarpino
Permissions may be sought directly from Eclipse Engineering LLC:
Fax: (925) 262-1757
E-mail: info@eclipseengineer.com
Appendix B: Advanced Geometry..................................... 391
B.3 Introduction to Transformation Matrices .........................................406
B.4 Combinations of Transformations...................................................415
B.5 Transforming Points and Vectors....................................................418
B.6 Mathematics of Combining Transformations....................................423
You may find helpful links here:
http://sketchucation.com/forums/viewtopic.php?f=180&t=10142&p=573943&hilit=automatic+sketchup#p269709