Hi,

Do u know an algorithm to convert a matrix to a quaternion?

Hi,

Do u know an algorithm to convert a matrix to a quaternion?

Only orthogonal matrix A can be converted.

You have to find vector v=<x,y,z> such that

```
Av=v, | |v| | =1
```

So A is a rotation around v.

You have to find angle (alpha) of rotation.

Quaternion you want to find is given by:

q=< cos(alpha/2.),

x*sin(alpha/2.),
y*sin(alpha/2.),

z*sin(alpha/2.)>