Adaptation of quadric metric simplification to MPEG-4 animated object

Our work focuses on the simplification of MPEG-4 avatar models. Similar to other general purposed 3D models, these avatars often claim complex, highly detailed presentation to maintain a convincing level of realism. However, the full complexity of such models is not always required, especially when a client terminal - for the reason of portability and cost reduction - cannot or does not necessarily support high complex presentation. First, we deploy the well-known 3D simplification based on quadric error metric to create a simplified version of the avatar in question, taking into account that the avatar is also a 3D model based on manifold mesh. Within this general scope, we introduce a new weight factor to overcome an uncertainty in choosing target for decimation. Next, exploiting the biomechanical characteristic of avatars - having the underlying skeleton structure - we propose an adaptation of the simplifying technique to avatars. The concept of bones is taken into account as either a boundary constraint or a cost-component for the quadric error. Encouraging results can be obtained with these modified procedures.