Macross Plus (マクロスプラス, Makurosu Purasu?) is a four-episode anime OVA and theatrical movie in the Macross series. It was the first sequel to the original Macross television series that took place in the official timeline (Macross II was quickly retconned by series creator Shouji Kawamori as a parallel world story in the Macross universe). Plus was a groundbreaking combination of traditional cel and computer-generated animation at the time of its release, paving the way for the incorporation of more computer-generated imagery in Japanese Animation.

Source: Wikipedia