Research And Application Of Efficiency Real-time Simulation Of Deformable Objects

The deformable objects simulation is becoming more and more popular due to the widely use. It is used in many area of computer graphics animation, such as the motion of cloth in interactive video games, the render of human soft tissues in surgery training system. Allowing the user to interact with the simulation system brings new research problems at the same time. These problems are a combination of solving the differential equation of large system, collision detection, collision response modeling. What’s more, many problem still lack appropriate solution, especially when the simulation must be real-time. So the study of deformable objects’ real-time simulation is significant meaningful.The simulation of deform objects is an active topic which focus on the motion and efficiency of deform objects in virtual reality. The simulation of interactive with others in virtual environment is also an active topic in many subject area. This kind of simulation is an interdisciplinary field research subject, which include computer graphics, thermodynamics, fluid mechanics and dynamics. Different from rigid bodies, deformable objects’ shape can change while simulating. This means that the distance between two particles is not fixed. Despite the unfixed distance, it’s essential to keep the shape to some degree(not as the fluid).The traditional approach for the simulation of dynamic systems in computer graphics are force based. Therefore, many well established methods have been used in graphics simulation such as the Mass-Spring Networks, the Finite Element Method(FEM), the Boundary Element Method. In general, these methods provide not accurate but visual plausible simulation.In the last years the class of position-based methods has become popular in the graphics community. Position-based methods are tailored particularly for use in interactive environments. They provide a high level of control and are stable even when simple and fast explicit time integration schemes are used. In addition, with the position based approach it is possible to control the integration directly thereby avoiding overshooting and energy gain problems in connection with explicit integration. Due to their simplicity, robustness and speed these approaches have recently become very popular in computer graphics and in the game industry.The research content and the main work of my paper will be as follows:First, analyze the traditional method, such as the Mass-Spring Networks, the FEM and their drawbacks.Second, dissect the Position-Based Approaches including PBD, Shape Matching and their advantage over traditional methods. In this part, a detail study of the two approaches will be displayed.For the PBD, I will discuss the basic simulation algorithm, after then, I’ll come up with some constraints and explain its application scenarios. Besides, I’ll also optimize the PBD use Hierarchical Position Based Dynamics(HPBD). As for this point, it’s refer to accelerate the convergence rate. That’s because slow convergence rate leads to stretchy cloth. Thus obtain the simulation result to be as real as possible.For the Shape Matching, I will also first discuss its basic algorithm. Besides, I’ll show its special use in the simulation of elastic objects. What’s more, I’ll also come up with a optimize method-Goal Position Limiting Shape Matching(GPL-Shape Matching). That’s because the basic shape matching algorithm may bring some over-shooting problems.Third, based on what has been described above, I’ll realize the real-time simulation of cloth and elastic body.