一种用于软组织变形仿真的动态质点弹簧模型

A Dynamic Mass Spring Model for Simulation of Soft Tissue Deformation

针对可以用面模型近似表示的软组织,提出一种简单可靠的软组织变形仿真的质点弹簧建模方法。虚拟体弹簧动态地产生一种约束力表现软体的体特征,准静态方法求解模型使仿真效果更好;用修改的蝶形细分方法把比较粗糙的表面网格模型先细分成若干细节层次,仿真时依质点所受力的大小动态细分,以提高模型仿真的精确度。实验表明:所提出的方法确实增强了软组织变形仿真的体积感;局部动态细分模型与粗网格模型的计算量相差甚少,但其计算精度却提高多倍。

A simple and reliable mass spring modeling method was proposed, which is adapted to the simulation of the soft tissue that can be approximately represented by surface mesh. The concept of virtual volumetric spring was introduced for simulating volumetric information of the soft tissue first. Then a dynamic local subdivision method was given to improve the simulation precision, which is based on the modified butterfly subdivision algorithm and processed on two-stage offline and online. In the offline stage, the base mesh was subdivided into some level of detail meshes. On simulating the online stage, the local subdivision mesh was generated according to some criteria such as stress strength. The experiment results show that the presented method enhances indeed the sense of volume for soft tissue deformation in real time simulation. The computation cost of the local subdivision model is almost the same as the initial coarser model but performs higher computational precision.