Hm, maybe it's disabled in the code ? That would explain why they didn't bother to change the values. Karl found this in the code, maybe it's related and you can add the z-axis :

// convert to block and vertex

              long tileCol;

              long tileRow;

 

              land->worldToTile( data->vector, tileRow, tileCol );

 

              int blockI = tileCol/20;

              int blockJ = tileRow/20;

              

              data->blockNumber = blockJ * land->blocksMapSide + blockI;

              tileCol -= blockI * 20;

              tileRow -= blockJ * 20;

              

              data->vertexNumber = tileRow * 20 + tileRow;

              countObject(data);

              

              data++;

       }