求大神指点迷津啊！模拟鸟拍动翅膀的问题

leonhu1992

模拟扑翼飞行，UDF如下：
#include "udf.h"
#include "dynamesh_tools.h"

real w, pi, Aroll, Apitch, roll, droll, pitch, dpitch, frequency, T;
real Ar, Ap, Ay;

DEFINE_CG_MOTION(flapleft, dt, v_cg, omega, time, dtime)

{
Thread *t;
face_t f;
NV_S(v_cg, =, 0.0);
NV_S(omega, =, 0.0);

if (!Data_Valid_P())
{
Message("Wrong\n");
return;
}

t=DT_THREAD((Dynamic_Thread*)dt);

frequency = 5.0;

pi = 3.141592654;

/* define motion variables */

Ar = 30.0; /*roll amplitude*/
Ap = 5.0; /*pitch amplitude*/
Ay = 0.0; /*yaw amplitude*/

Aroll = Ar*pi/180.0; /*conversion to radians*/
Apitch = Ap*pi/180.0; /*conversion to radians*/

w=2.0*pi*frequency; /*omega (radians)*/
T=1.0/frequency;

roll = Aroll*sin(w*time + pi/2);
droll = w*Aroll*cos(w*time);

pitch = Apitch*sin(w*time);
dpitch = w*Apitch*cos(w*time);

/*euler angles initial frame mod 1*/

omega[1] = -droll;   
/*omega[1] = dpitch*1.0*cos(roll);*/
/*omega[2] = -dpitch*1.0*sin(roll);*/

Message("time:%f omegax:%f omegay:%f omegaz:%f \n", time, omega[0], omega[1],omega[2]);
}

只是模拟上下拍动哟！

动网格预览：时间步长：0.0025s   步长：1000步


问题是：动网格预览时，出现翅膀整圈整圈的旋转，求各位大侠前辈，指点迷津啊！小的先行谢过！