Constrained Deformations For Polygonal Mesh Models Based On Space Transformation

3D models'deformation is very important in computer animation. With the development of 3D animation, strict standards for 3D deformation are demanded. The researchers need to improve the quality of 3D models'deformation to make the 3D animation meet the society's demands better. For this purpose, a lot of researchers at home and abroad have paid much attention to the 3D models'deformation and it becomes the focus of research.This paper introduce the experiment platform briefly in the second chapter, Include basic knowledge of OpenGL,the data format of 3D model and the meaning of keyword. The OBJ files of the three-dimensional model are read and drawn by OpenGL.These efforts for the desired area and surface reconstruction.After analyzing the algorithm presented by other scholar, this paper present a method of 3D models'deformation. The desired local vertices area ready for deform is determined by calculating the distance between constraint and mesh vertices. If the result of primary constraint not accurate, calculate it again by plane in 3D.this is secondary constraint. The secondary constraint result meets the users'demand substantially and depresses the interference of undesirable mesh vertices. The researcher need to deform the 3D model after determined the desired local vertices area ready for deform. The author combine geometric transformation with potential function efficiently to make every vertex of 3D model has respective weight. According to the weight calculate by potential function. The user can perform the experiment such as translation, scaling and rotation operations in three dimensional spaces. The vertices'weight show trend of monotonic increasing or decreasing because the experiment make use of the distance between the plane and vertices when the user compute it again . So depress the interference of collapse and fracture by this way. At last, According to the linear transformation of vectors, the author proposes a new method of deformation. The desired vertices of 3D model can be moved to the spherical surface whose centre is the constraint and the radius is effect radius, expand the method of deformation.Lots of experiment results showed that the deformation method is highly stable, accurate and natural, can better deform the 3D models.