Research On 3D Facial Expression Synthesis Based On Motion Capture

This thesis summarizes the latest development of facial expression synthesis at home and abroad,classifies the existing methods,and makes a detailed analysis of their respective advantages and disadvantages.On this basis,the optical motion capture system is used for in-depth discussion,and a solution to synthesize facial expressions using motion capture system is proposed,including the collection and optimization of facial expression data,the extraction of facial expression features,the construction of specific facial models,the synthesis of facial expression animation and the design of facial expression synthesis system.Design and implementation.Specifically,the work of this thesis mainly includes the following aspects:(1)A high-precision facial expression acquisition and extraction scheme is proposed.ViconCara facial motion capture system is used to collect actors'expressions.The collected facial expression data are tracked,recorded and processed in real time through CaraPost software,and the three-dimensional spatial coordinates of facial expression data and feature points are obtained.(2)A scheme of using FaceGen Head Generator and Mayaa software to obtain a specific actor's face model is proposed.The general face model obtained by using FaceGen Head Generator method is used to construct the subsequent specific face model.(3)A method of constructing a specific facial model based on motion capture data and RBF interpolation algorithm is adopted.In order to obtain a specific facial model,this thesis needs to locally deform the facial model.According to the principle of RBF interpolation function deformation,a smooth approximate interpolation function is constructed,and the mesh model is adjusted by collecting three-dimensional coordinates of facial feature points.The coordinates of feature points and non-feature points make it more consistent with the physiological characteristics of human face.(4)This thesis constructs a specific facial model from the coordinates of feature points and the calculated non-feature points,and synthesizes six basic facial expression animations and facial models in MotionBuilder.(5)A facial expression synthesis system based on Unity3D game engine is designed.The six basic expressions are displayed in Unity engine through the control of C#language script.