Explicit and implicit animation with fuzzy constraints of a versatile multi-body system for virtual hand surgery

摘要

This work is designed to control the movement of hand structural agents under external action, using the implicit animationndriven by explicit animation technique (AI-CAE technique). Starting from the configuration of a hand at rest obtained by an3D scanner and after meshing of the structural agents, we seek the configuration of the rigid agents under orthopaedicnsurgeon external action and interacting reliance of deformable and rigid agents. We have developed a model andnsoftware tools to answer this interactive application with adaptive execution. The first contribution comes from notationsnand definition of a versatile multi-body system dedicated to the explicit and implicit animation. The second contributionncomes from the implicit animation driven by explicit animation itself, and from its ability to mimic the role of cartilagesnand ligaments. The resulting technique is applied to the bone structure consistency of a specific human hand in the contextnof virtual hand orthopaedic surgery. The versatile specific multi-body is made up of hierarchical interacting agentsnconceivable as a construction set of rigid bones with cartilages–ligaments and underlying links. The explicit animationnproduces a desired configuration from geometric command parameters of torsion, flexion, pivot and axis shifting, given in anscenario subdivided into temporal sequences. The implicit animation controls the movement by implementing a physicsbasednmodel and fuzzy constraints of position and orientation. It gives better configuration than the explicit animationnbecause it takes into account the interactions between agents, and it gives a neat solution without the problems ofncomplexity due to geometric modelling. A methodology based on the AI-CAE technique is discussed, medical expertisenand validation tests are presented. Copyright # 2011 John Wiley & Sons, Ltd.