Virtual character animation is a very important area of study. Research in this field has provided many different solutions and systems to develop 3D human platforms. These areas eventually branched into many areas of investigation to explore the creation of realistic virtual humans, including appearance, expressions, emotions, reasoning, communication and behaviour. Whilst many projects and methodologies have been developed, there was no common standard until the Movie Picture Experts Group (MPEG) proposed a broad specification for facial and body animation, defined as the MPEG-4 FBA (facial and body animation). The effect of this standard was the development of a number of MPEG-4 compliant character animation frameworks, which use its proposed parametric solution which permits to compare different methodologies used to create virtual faces. In this paper, we propose a comprehensive survey of state-of-art of MPEG-4 facial animation (FA) character animation frameworks, define common criteria to compare them and perform experiments to evaluate their functionalities, usability, compliance to MPEG-4, animation quality, performance and coarticulation techniques, support for embodied character ability, compatibility between them and model simplification solutions. In particular, we compare complete frameworks such as Greta and Xface to our framework Charisma, including some of the variations and existent subsystems present in these systems.
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