i’m using the artk+ tracker. the tracker only has the possibility to get a matrix. my problem is to find out the parts of the matrix which are responsible for the rotation around the x/y/z axis. i need seperate values because i want to control a color-output with the rotation.

perhaps the rotation is even in the quaternion in the artk+ tracker?

there is no node to do this directly. but you are right, the quaternion is the right choice, now just google for ‘quaternion to euler angles’, like here

here is some code, the node Expr (Value) just waits to handle the expressions, then with >, < and Switch you can handle the if cases for the singularities…