to_matrix

Converts a Euler into a transformation matrix expressing the extrinsic composition of rotations described by the Euler angles.

The rotations are applied over the reference frame axes in the order associated with the Euler; for instance, if the order used to initialize this is graphene_euler_order_xyz:

* the first rotation moves the body around the X axis with an angle φ * the second rotation moves the body around the Y axis with an angle of ϑ * the third rotation moves the body around the Z axis with an angle of ψ

The rotation sign convention is right-handed, to preserve compatibility between Euler-based, quaternion-based, and angle-axis-based rotations.

Parameters:

this	a Euler
res	return location for a Matrix