Modeling Technology Of Articulation Animation In A Fluid Environment

With the rapid development of computer graphics, software and hardware, thetechnology of articulated animation based on the physical mode has gradually becomethe research focus of computer animation. Nevertheless, due to the complex modelingand the limit of software and hardware, the articulated animation under the action ofcomplicated scene has been studied by but few people. The articulated animation in afluid environment can show lifelike swimming and flight effect acted by vertebrates androbots and it plays an important role in so many areas, such as film animation,biological swimming mechanics, video games and diving robot. In addition, it canprovide calculating basis in a certain extent for articulated animation in other complexstress scene.This thesis comes from National ’863’ program ’Real-time model and renderingtechniques of Crowd Animation in virtual environment’ and National ’863’ program’Techniques and system of3D physics engine and efficient rendering’. At first, we studyand analyse current related representative techniques which focus on articulatedanimation, including articulated body modeling technology, control technology andfluid-solid coupling. And then we design and implement the articulation animationsimulation system which is used in a fluid environment. The main innovation of thisthesis is that it presents an improved proportional-derivative controller and the forcemodeling which the articulated body uses in a fluid environment, and then implementsthe articulation animation simulation system which is used in a fluid environment withthese modeling techniques.Articulated body modeling is very important in these key technologies. This isbecause its coordinate system serves as the standard of the entire modeling calculatingprocess. We realize this modeling based on Lagrange dynamics with previous research.This method has less unknown than Newton-Euler equation, so it can improve thecalculating efficiency. In the dynamic computing, the articulated body is fundamental.Only when the dynamics modeling equation has been established, the follow-up controltechnology and couple modeling can be founded. In order to make the articulated body do active movement, we introduce thecontroller technology to make it track the pre-set trajectory and put forward acalculation based on it. In the impact of Euler’s method(numerical calculation), it cantrack the reference trajectory stably and accurately and also can bring the effect comingfrom generalized force and constraint force in the process of driving data.We provide a kind of normal stress and tangential friction influence model throughthe extraction of parameters in Navier-Stokes equation which is used in fluid simulation.And then we translate the model into generalized coordinate system and serve as theinfluence force produced by fluid.At last, this thesis implements the articulation animation simulation system whichis used in a fluid environment and then applies the system to ‘fluid-solid coupling’project. Subsequently, this thesis summarizes the research results and looks to furtherwork.