How to get vertex normals from a shape-key in Python? I'm trying to create an exporter for a format, which includes shape key support. This format requires both vertex coordinates and normals to be specified. This should be logical, because the vertex selected on the image below won't have the same normals:

 

Comparing it to this one:



But I actually haven't found any way to export shape key normals. Both Bmesh Vertex and ShapeKey Vertex only store the coordinates.

Is there any way to get them?
The only way I can think of is to use Object.to_mesh() and read normals from this temp mesh datablock, before freeing it (see also the doc):

me = my_ob.to_mesh(scene, True, 'Render', False, False)
for v in me.vertices:
    print(v.normal)
bpy.data.meshes.remove(me)


Quite obviously, you need to set the influence of your shape key accordingly first.