Unity 利用Quaternion.LookRotation API 将旋转矩阵转换成四元数

Quaternion.LookRotation

 

1. private staticQuaternion QuaternionLookRotation(Vector3 forward,Vector3 up)
2. {
3.     forward.Normalize();
5.     Vector3 vector= Vector3.Normalize(forward);
6.     Vector3 vector2= Vector3.Normalize(Vector3.Cross(up, vector));
7.     Vector3 vector3= Vector3.Cross(vector, vector2);
8.     var m00= vector2.x;
9.     var m01= vector2.y;
10.     var m02= vector2.z;
11.     var m10= vector3.x;
12.     var m11= vector3.y;
13.     var m12= vector3.z;
14.     var m20= vector.x;
15.     var m21= vector.y;
16.     var m22= vector.z;
19.     float num8= (m00+ m11)+ m22;
20.     var quaternion= newQuaternion();
21.     if(num8 >0f)
22.     {
23.         var num= (float)Math.Sqrt(num8+ 1f);
24.         quaternion.w= num *0.5f;
25.         num =0.5f / num;
26.         quaternion.x= (m12- m21)* num;
27.         quaternion.y= (m20- m02)* num;
28.         quaternion.z= (m01- m10)* num;
29.         return quaternion;
30.     }
31.     if((m00 >= m11)&& (m00>= m22))
32.     {
33.         var num7= (float)Math.Sqrt(((1f+ m00)- m11)- m22);
34.         var num4= 0.5f/ num7;
35.         quaternion.x= 0.5f* num7;
36.         quaternion.y= (m01+ m10)* num4;
37.         quaternion.z= (m02+ m20)* num4;
38.         quaternion.w= (m12- m21)* num4;
39.         return quaternion;
40.     }
41.     if(m11 > m22)
42.     {
43.         var num6= (float)Math.Sqrt(((1f+ m11)- m00)- m22);
44.         var num3= 0.5f/ num6;
45.         quaternion.x= (m10+ m01)* num3;
46.         quaternion.y= 0.5f* num6;
47.         quaternion.z= (m21+ m12)* num3;
48.         quaternion.w= (m20- m02)* num3;
49.         return quaternion;
50.     }
51.     var num5= (float)Math.Sqrt(((1f+ m22)- m00)- m11);
52.     var num2= 0.5f/ num5;
53.     quaternion.x= (m20+ m02)* num2;
54.     quaternion.y= (m21+ m12)* num2;
55.     quaternion.z= 0.5f* num5;
56.     quaternion.w= (m01- m10)* num2;
57.     return quaternion;
58. }