I'd guess before, they've been in the CGI business for quite a while. I saw a presentation from Milton back in 2000 (I'm also a VUW CS grad) with pictures of the render wall.

At one point they bought the building of an ice cream factory in Miramar because it already had a massive electrical feed.

They employ a fair few people in Wellington, my neighbour used to work for Weta as a sysadmin. Everyone was a contractor, doing 10 hour days. Not my scene.