If you always wanted to know why in all recent films that have digital actors they don't look that convincing you might be interested in this read:
A bright shining lie - Synthespians, why we don't like them and their future role in cinema
I'm talking about digital actors in a way they appear in the Final Fantasy movie or Beowolf. A full substitute for a human actors. Digital stuntdoubles are not so much the focus of the article.
Hope you enjoy the read.