At 0:13 of this video clip, the director of the movie says:
What's so exciting is that we are capturing the actors' performance, tracking that into these photo reliefs.
Photo-relief is defined in this dictionary as
An image in relief produced by a photographic process
Which I doubt makes any sense in the movie's context.
So I've looked at another definition here:
A photograph having relief information added.
A photograph of a relief model .
But I still can't wrap my head around the meaning of "photo reliefs" as used by the director.
What does "photo reliefs" mean in context?