四阶龙格－库塔法模拟粒子三维空间轨迹，需给出立场函数,3D simulation of particle dynamic trajectories by Fourth-order Runge- Kutta method

MIT计算机图形学作业，粒子系统。完美实现风力场，水流和火焰场等。实现了四阶龙格库塔积分法和梯形法等。实现了所有功能。-MIT computer graphics operations, particle system.Perfect realization of wind field, flow field and flame, etc.Implement the fourth order runge kutta integration method and trapezoidal metho