Mass Effect 2 - Assembling the Art

Commercial site Pixologic has a special feature on the art in Mass Effect 2.  Over 10 pages, Assembling the Art is an interview with a variety of ME2 art staff emphasising the technical development process.  It's no doubt meant to be a promo vehicle for Pixlogic's products but does contain some interesting insight:

Jaemus Wurzbach – Lead Character Artist:
We break our characters into different chunks. The vast majority -- especially the aliens -- are made up of two chunks: a head and a body. We do this because our game has such a huge focus on conversations. We need to get as much resolution as possible in the faces because our designers love to do extreme close-ups. If we make creatures that are never intended to be in conversations, like the Collectors, then we keep them to one chunk. We try to keep each chunk to around three textures. We have a color diffuse, a normal map and a specular stack. We break the specular stack into 4 sections: the R,G,B and Alpha channels and then slot 4 grayscale images into that. Typically these maps might include a specular map, a specular power map, an emissive map, and various masks we might need to control special parameters we create in our shaders. So a character like Grunt or Mordin would run about 6 textures each; 3 for the head and 3 for the body.