Starting blender 2.78, there are new use flags:
# equery u blender-2.78
[ Legend : U - final flag setting for installation]
[ : I - package is installed with flag ]
[ Colors : set, unset ]
* Found these USE flags for media-gfx/blender-2.78:
U I
+ - boost : Enable features depending on boost.
+ - bullet : Enable Bullet (Physics Engine).
- - collada : Add support for Collada interchange format through media-libs/opencollada.
