This paper presented the solution of normal vector by using the method of the accumulative hypotenuse trispline curve.
采用累加弦长三次样条参数曲线，先求出离散点处两个方向的切矢，进而求解出该离散点的法矢。
2
The existing algorithms include equivalent left and right curve Angle by definition, normal section line method and tangent projection etc.
有关的算法有根据定义的左右曲面角相等，法截面法和切向投影等。
3
Crowd excitation is simulated by random method according to normal footfall force curve and other individual factors such as distribution of crowd, step frequency and physiological characteristics.