I’ve added a new article, Blending in Detail, written together with Colin Barré-Brisebois, on the topic of blending normal maps. We go through various techniques that are out there, as well as a neat alternative (“Reoriented Normal Mapping”) from Colin that I helped to optimise.
This is a companion discussion topic for the original entry at https://blog.selfshadow.com/2012/07/10/blending-in-detail/