In Part 2, we duplicate our low poly model to create a high poly version, and we also unwrap the original low poly.
We export an fbx of the low poly, and an obj of the high poly. (In the video, I mistakenly export the high poly as an fbx too. however, Zbrush wont accept fbx files!
NB - If you dont have zbrush, its totally fine to skip part 3 and continue on to substance painter in part 4.