I'm going to look at the Concept Artist as up to now it has inspired me the most, as it has most people I have spoken to.
Concept Artists are brought it in to produce illustrations that capture the feel of a scene or character. This could be throughout a film or just at certain points to help the animators know where they are working towards.
The concept artists often work closest with the Artistic Director or Graphic Designer. This allows them to work together to discuss and conceptualise the look and feel of the film well before shooting gets under way or the animation itself. This kind of work is very specialised and requires a great deal of skill, there is limited demand for this work.
The artist will often work alongside the draughtsmen in the studio and the specialist researchers crew. This will allow them to work in a close nit group with minimal cross over time, exchanging ideas in the fastest way possible.
Concept artists have a highly acclaimed roll as there work needs to capture moments in the film, this requires therefore crisp accurate drawings that are also striking.
The typical route of which the concept artists follows is:
Discussion ad production of ideas with Production Designer
Presentation to the Producer, Director etc
Discussion followed by ideas that the producer etc have
Re-evaluation and final concepts