Note: I did not make this, simply uploading to Veoh becuase nico video doesn't let you embed.
Via Sankaku: http://www.sankakucomplex.com/2009/01/12/megurine-luka-erotically-illustrated/ In this video, the artist who calls himself Xai creates the lineart in Systemax SAI, and then colors in Photoshop. He said that drawing Megurine's clothing was a hassle, so he got rid of some parts-- in the chest area. If you ask me, laziness really did help out. This is one of the more popular images of her around. You can see Xai's artistic profile through Sankaku. -Enjoy