Blender finally added the possibility to use custom normals in version 2.74. YAY. I've been playing with them to export and import a custom file format.
For example: I created the custom normals for a mesh, then call the calculate split normals and tessfaces methods
C.active_object.data.calc_normals_split()
C.active_object.data.update(calc_edges=True, calc_tessface=True)
and I can see the custom normals I expected
Vector(C.active_object.data.tessfaces[0].normal)
Vector(C.active_object.data.tessfaces[0].split_normals[0])
But if I try to use the Set Split Normals Modifier to create the normals, and even thou I can see the new normals working in the 3Dview, I can't find a ways to access those normals without appliying the modifier.
Can it be done? How can access the new normals data without applying the modifier?
obj.to_mesh(scene=bpy.context.scene, apply_modifiers=True, settings='PREVIEW')
then freeing the mesh after usage $\endgroup$ – Jaroslav Jerryno Novotny Apr 3 '15 at 11:13