虚拟人骨架驱动皮肤变形的改进的热平衡法

摘要

An improved thermal equilibrium weight assignment algorithm is proposed.Firstly,the skeleton is extracted,and the virtual human surface model is obtained.Then the projection position of the skin vertex to the bone vector is calculated.After that,the binding relationship between the skin and bone is determined through the projection position of the skin to the bone vector,and the new initial condition of the thermal equilibrium equations is obtained.Finally,the related weights of the skin and bone are obtained by solving the thermal equilibrium equations,and a lifelike virtual human skin-deforming animation is drived by using dual quaternion skinning algorithm.Experimental results show that this method can not only solve the skin upheaval problem caused by large range of joint rotation around the joint transition area effectively,but also avoid the skin collapse phenomenon and "candy wrapper" effect.%在骨架驱动虚拟人皮肤变形中,传统热平衡法由于权重分配不均造成大幅度关节旋转运动时皮肤凸起的失真现象,针对上述问题,提出一种改进的热平衡权重分配算法.首先,提取虚拟人骨架,得到虚拟人表面模型;然后,计算皮肤顶点到骨骼向量的投影位置;接着,通过判断皮肤顶点的投影相对骨骼向量的位置来确定骨架和皮肤的绑定关系,得到新的热平衡方程初始条件;最后,求解热平衡方程得到骨架和皮肤关联的权重,并运用对偶四元数蒙皮算法驱动了逼真的虚拟人皮肤变形动画.实验结果表明,改进方法有效解决了大幅度关节旋转运动时关节交接处出现的皮肤凸起问题,且避免了皮肤塌陷现象和“裹糖纸”效应.