creo3 config.pro option documentation for: INTF3D_OUT_FORCE_SURF_NORMALS 
intf3d_out_force_surf_normals
yes
, no
*
Controls normals of nonanalytic surfaces.
VDA always forces surface normals. Although this option facilitates data exchange with CATIA, it may also facilitate other receiving CAD systems.
yes
- Forces the surface normals to point in a consistent direction.
no
- Does not force the surface normals to point in a consistent direction.