Research Technology, 3D Character Models And Animation Are Generated Automatically

In this paper we propose an integrated approach to generate computer animations. The approach consists of three steps. Firstly we achieve3D character models from preprocessed3D point data, in conjunction with some of the reverse engineering technology. Next the skeleton of the character models is extracted according to anthropotomy. Finally, the3D character animation is automatically generated by applying the linear mixed skin technology, based on the3D character model and skeleton, as well as BVH motion capture data files. The integration for automatically generating the3D character models and animation has some advantages, such as high efficiency, low cost, and very little artificial participation.The paper mainly includes:(1)The approach to automatically generating3D character modelsAfter getting the figure surface’s3D point cloud data using three-dimensional scanner, we make the preprocessing of these point cloud data to find the major and minor axes, combining with the variance knowledge. Furthermore we can obtain the projection plane, which divide these point cloud data into two parts. We use the Delaunay triangulation algorithm to generate triangular mesh. In order to improve performance, we restrict the distance to search the third point, and take full advantage of human physiological symmetric characteristics. Once getting the front and the rear triangle meshes, we can map the two-dimensional triangular mesh back to3D space; according to the relative position of the points. So3D character models are automatically generated.(2) Skeleton extraction of character modelWe can identify five end feature points of the human body according to geodesic distance. Then we find the approximate location of the15other body joint points, starting from the five feature points, according to the knowledge of anatomy of the human body, the human body rigid characteristics of the skeleton and the principle of two points determining a straight line. Based on the minimum value of the central angle algorithm and the contours similar circle rate algorithm, we can draw the exact location of the15joint points. Finally these joint points are connected in turn to generate a three-dimensional human body model skeleton according to the human skeleton topology.(3) The approach to automatically generate3D character animationCombinning BVH motion capture files with skin deformation technology, we can automatically generate3D character animation based on the obtained3D character models and the human skeleton. In general, we need to match the previous3D character models and skeletons with standard body posture. This article proposes a method of the local coordinate system for skeleton aligned matching. Determining the body towards by the hip joint as a starting point, we can get each joint’s coordinate frame and seek out the transformation matrix of the coordinate frame according to the bones hierarchy in the BVH file, then apply the transformation matrix to the joint and its subsidiary joints.