Research On Dynamic Simulation Of Avatar Dress Based On Ellipsoid Fitting

3D clothing simulation is one of the research hotspots in the field of computer graphics.The simulation process is accompanied with a huge amount of computation.The High-quality simulation,on the low-end hardware platform and interactive environment,is still a difficult research point.This thesis takes the reality of simulation and real-time as the goal and studies the 3D human dress simulation technology.The research includes physical simulation of fabric,virtual human modeling,human model preprocessing,ellipsoid fitting,collision detection and collision response processing.Finally,we build a real-time virtual human dress simulation system.The fashion design software designs,then exports garment models for a realistic and stable clothing fabric model.The research uses the vertex of the triangle mesh in the clothing model as physical model mass points.And it defines the lines which connect the mass points as springs to establish the constraint mass-spring model.Achieve the dynamic simulation effect by adding wind force,gravity and using Verlet numerical integration method.For the traditional complex dynamic update of bounding boxes and the low efficiency of collision detection response,this thesis uses the ellipsoid with higher fitting as the primitive bounding box.First,feature joint points at the end of the model are extracted.Then,the virtual human model bone extraction and segmentation is achieved by combining the linear relationship of human body height and human body structural features.The segmented human body parts are individually subdivided by using K-means clustering algorithm based on pruning optimization.Finally,a series of ellipsoid bounding boxes that closely surround the human body are generated.In order to speed up the construction of the ellipsoidal bounding box and realize the simulation of the dress under the body movement state.This thesis proposes a method based on template frame information and linear interpolation.The method effectively improves the performance of time-consuming while updating the bounding boxes.For the collision response of ellipsoids,we present two different collision response processing methods during static and motion dressing processes.The experiments show that the method constructed by dynamic ellipsoidal bounding box,which is used in this paper can quickly achieve the human body fitting.At the same time,this method can simulate the dynamic change process of the fabric driven by the moving body effectively.Compared with the real fabric,the simulation effect is real and natural.