py3dframe.Frame.set_quaternion

Frame.set_quaternion(quaternion, *, convention=None, scalar_first=True)

Set the quaternion representation of the rotation between the parent frame and this frame in a specific convention.

The quaternion must be given as a array-like with 4 elements in the scalar first [w, x, y, z] or scalar last [x, y, z, w] convention.

See also

• attribute parent to get or set the parent frame.

• attribute convention to get or set the convention of the frame.

• attribute quaternion to get or set the quaternion in the convention of the frame.

• method get_quaternion() to get the quaternion in a specific convention.

• method set_global_quaternion() to set the quaternion between the global frame and this frame.

Parameters:

• quaternion (numpy.ndarray) – The quaternion between the parent frame and this frame in the given convention as an array-like with 4 elements.

• convention (Optional[int], optional) – Integer in [0, 7] selecting the convention. Defaults to the frame’s own convention.

• scalar_first (bool, optional) – If True, the quaternion is in the scalar first convention. Default is True. If False, the quaternion is in the scalar last convention.

Return type:

None

Examples

Lets create a default frame with convention 0.

from py3dframe import Frame

parent = ... # Define the parent frame if needed, otherwise parent=None to use the canonical frame.

frame = Frame.canonical(convention=0, parent=parent)

Lets assume, an application uses convention 4 to represent the transformation between two frames. The frame of reference of the application rotates and the new quaternion between the parent frame and this frame in convention 4 with scalar first convention can be extracted from the application.

import numpy

quaternion = numpy.array(...) # Extract the quaternion from the application.

frame.set_quaternion(quaternion, convention=4, scalar_first=True) # Set the quaternion in convention 4 with scalar first convention.