I have the states:
$X = \begin{bmatrix} \alpha_{1} & \beta_{1} & \gamma_{1} & \alpha_{2} & \beta_{2} & \gamma_{2}\end{bmatrix}^{\mathsf{T}}$
and suppose I have the relation using ZYX Euler angles:
$h(X) = Rot(\alpha_{2}, \beta_{2}, \gamma_{2})Rot(\alpha_{1}, \beta_{1}, \gamma_{1})^{\mathsf{T}}$
Now, how do I get the jacobian $\nabla h$?