Qt3D doesn't follow the coding conventions when including headers

Including headers

    In public header files, always use this form to include Qt headers: #include <QtCore/qwhatever.h>. The library prefix is neccessary for Mac OS X frameworks and is very convenient for non-qmake projects.
    In source files, include specialized headers first, then generic headers. Separate the categories with empty lines.

     #include <qstring.h> // Qt class
     
     #include <new> // STL stuff
     
     #include <limits.h> // system stuff

    If you need to include qplatformdefs.h, always include it as the first header file.
    If you need to include private headers, be careful. Use the following syntax, irrespective of which module or directory whatever_p.h is in.

     #include <private/whatever_p.h>