As for realism vs fantasy, Disney did some great work in improving physical realism as part of making the highly fantastic Wreck It Ralph.[1] Once they had the knobs set up that accurately tune the physical properties of their materials, the artists were able to push certain properties beyond realistic values without having the result be completely fake looking. Multiple real time rendering systems, including the Unreal Engine, site this paper as a source for their new "Physically Based" material systems.

[1] https://disney-animation.s3.amazonaws.com/library/s2012_pbs_...