py3dframe.FrameTransform.dynamic

property FrameTransform.dynamic: bool

The dynamic attribute controls whether the transformation is affected by changes in the input or output frame.

Note

This attribute is settable.

The dynamic attribute is a boolean. If True, the transformation will be affected by the changes in the input frame or the output frame. Otherwise, the transformation will be frozen at the time of the transformation object creation or at the time of the change of the dynamic attribute to False.

Parameters:

dynamic (bool) – If True, the transformation will be affected by the changes in the input frame or the output frame.

Returns:

If True, the transformation will be affected by the changes in the input frame or the output frame.

Return type:

bool

Examples

Lets create a FrameTransform object with the global frame as input frame and a local frame as output frame.

import numpy as np
from py3dframe import Frame, FrameTransform
frame_E = Frame.canonical() # Input frame - Global frame
frame_F = Frame.from_axes(origin=[1, 2, 3], x_axis=[1, 0, 0], y_axis=[0, 1, 0], z_axis=[0, 0, 1]) # Output frame - Local frame

transform = FrameTransform(input_frame=frame_E, output_frame=frame_F, dynamic=True, convention=0)

Here dynamic is set to True, so the transformation will be affected by the changes in the input frame or the output frame.

X_i = np.array([1, 2, 3]).reshape((3, 1))
X_o = transform.transform(point=X_i)
print(X_o)
# Output: [[0.] [0.] [0.]]

print(transform.input_frame)
# Output: Frame(origin=[[0.] [0.] [0.]], x_axis=[[1.] [0.] [0.]], y_axis=[[0.] [1.] [0.]], z_axis=[[0.] [0.] [1.]])
print(transform.get_active_input_frame())
# Output: Frame(origin=[[0.] [0.] [0.]], x_axis=[[1.] [0.] [0.]], y_axis=[[0.] [1.] [0.]], z_axis=[[0.] [0.] [1.]])

# Now, we change the input frame
frame_E.origin = [1, 1, 1]

X_o = transform.transform(point=X_i)
print(X_o)
# Output: [[1.] [1.] [1.]]

print(transform.input_frame)
# Output: Frame(origin=[[1.] [1.] [1.]], x_axis=[[1.] [0.] [0.]], y_axis=[[0.] [1.] [0.]], z_axis=[[0.] [0.] [1.]])
print(transform.get_active_input_frame())
# Output: Frame(origin=[[1.] [1.] [1.]], x_axis=[[1.] [0.] [0.]], y_axis=[[0.] [1.] [0.]], z_axis=[[0.] [0.] [1.]])

Lets set dynamic to False, any modification of the input frame or the output frame will not affect the transformation.

transform.dynamic = False

X_i = [1, 2, 3]
X_o = transform.transform(point=X_i)
print(X_o)
# Output: [[1.] [1.] [1.]]

print(transform.input_frame)
# Output: Frame(origin=[[1.] [1.] [1.]], x_axis=[[1.] [0.] [0.]], y_axis=[[0.] [1.] [0.]], z_axis=[[0.] [0.] [1.]])
print(transform.get_active_input_frame())
# Output: Frame(origin=[[1.] [1.] [1.]], x_axis=[[1.] [0.] [0.]], y_axis=[[0.] [1.] [0.]], z_axis=[[0.] [0.] [1.]])

# Now, we change the input frame
frame_E.origin = [2, 2, 2]

X_o = transform.transform(point=X_i)
print(X_o)
# Output: [[1.] [1.] [1.]]

print(transform.input_frame)
# Output: Frame(origin=[[2.] [2.] [2.]], x_axis=[[1.] [0.] [0.]], y_axis=[[0.] [1.] [0.]], z_axis=[[0.] [0.] [1.]])
print(transform.get_active_input_frame())
# Output: Frame(origin=[[1.] [1.] [1.]], x_axis=[[1.] [0.] [0.]], y_axis=[[0.] [1.] [0.]], z_axis=[[0.] [0.] [1.]])

Warning

Notice that when dynamic is set to True, the transformation is unchanged when the user gives a new input frame or a new output frame. However, the input frame or the output frame of the transformation is updated. Use the get_active_input_frame() or get_active_output_frame() methods to extract the active input frame or the active output frame of the transformation.

When dynamic is set to False, if the user gives a new input frame or a new output frame, the transformation will unchanged too.

new_input_frame = Frame.from_axes(origin=[3, 3, 3], x_axis=[0, 1, 0], y_axis=[0, 0, 1], z_axis=[1, 0, 0])
transform.input_frame = new_input_frame
print(transform.input_frame)
# Output: Frame(origin=[[3.] [3.] [3.]], x_axis=[[0.] [1.] [0.]], y_axis=[[0.] [0.] [1.]], z_axis=[[1.] [0.] [0.]])
print(transform.get_active_input_frame())
# Output: Frame(origin=[[1.] [1.] [1.]], x_axis=[[1.] [0.] [0.]], y_axis=[[0.] [1.] [0.]], z_axis=[[0.] [0.] [1.]])

When dynamic is set to to True, the transformation instantly takes into account the new input frame or the new output frame.

transform.dynamic = True
print(transform.input_frame)
# Output: Frame(origin=[[3.] [3.] [3.]], x_axis=[[0.] [1.] [0.]], y_axis=[[0.] [0.] [1.]], z_axis=[[1.] [0.] [0.]])
print(transform.get_active_input_frame())
# Output: Frame(origin=[[3.] [3.] [3.]], x_axis=[[0.] [1.] [0.]], y_axis=[[0.] [0.] [1.]], z_axis=[[1.] [0.] [0.]])