      //                                                   (FOR XML EXPORT ONLY)
      //                                           MATERIAL ASSIGNMENT IN TARGET VOLUMES
      //                                                      PIXEL MODULE
      //
      //  Top View 
      //        ------------------           y
      //        |                |           ^
      //        |     Hybrid     |           |
      //        |       (1)      |           +----> x
      //        ------------------    
      //                                             z
      //                                             ^
      //  Side View                                  |
      //         ================ Hybrid  (1)        +----> x
      //         ---------------- Sensor  (2)
      //         ================ Chip    (3)
      //
      // Chip(3) volume can contain Bumps and any other material for simplification.
