scipy.spatial.transform.Slerp

class scipy.spatial.transform.Slerp(times, rotations)

Spherical Linear Interpolation of Rotations.

The interpolation between consecutive rotations is performed as a rotation around a fixed axis with a constant angular velocity [1]. This ensures that the interpolated rotations follow the shortest path between initial and final orientations.

Parameters:

times : array_like, shape (N,)

Times of the known rotations. At least 2 times must be specified.

rotations : Rotation instance

Rotations to perform the interpolation between. Must contain N rotations.

References

[1]	(1, 2) Quaternion Slerp

Examples

>>> from scipy.spatial.transform import Rotation as R
>>> from scipy.spatial.transform import Slerp

Setup the fixed keyframe rotations and times:

>>> key_rots = R.random(5, random_state=2342345)
>>> key_times = [0, 1, 2, 3, 4]

Create the interpolator object:

>>> slerp = Slerp(key_times, key_rots)

Interpolate the rotations at the given times:

>>> times = [0, 0.5, 0.25, 1, 1.5, 2, 2.75, 3, 3.25, 3.60, 4]
>>> interp_rots = slerp(times)

The keyframe rotations expressed as Euler angles:

>>> key_rots.as_euler('xyz', degrees=True)
array([[ 14.31443779, -27.50095894,  -3.7275787 ],
       [ -1.79924227, -24.69421529, 164.57701743],
       [146.15020772,  43.22849451, -31.34891088],
       [ 46.39959442,  11.62126073, -45.99719267],
       [-88.94647804, -49.64400082, -65.80546984]])

The interpolated rotations expressed as Euler angles. These agree with the keyframe rotations at both endpoints of the range of keyframe times.

>>> interp_rots.as_euler('xyz', degrees=True)
array([[  14.31443779,  -27.50095894,   -3.7275787 ],
       [   4.74588574,  -32.44683966,   81.25139984],
       [  10.71094749,  -31.56690154,   38.06896408],
       [  -1.79924227,  -24.69421529,  164.57701743],
       [  11.72796022,   51.64207311, -171.7374683 ],
       [ 146.15020772,   43.22849451,  -31.34891088],
       [  68.10921869,   20.67625074,  -48.74886034],
       [  46.39959442,   11.62126073,  -45.99719267],
       [  12.35552615,    4.21525086,  -64.89288124],
       [ -30.08117143,  -19.90769513,  -78.98121326],
       [ -88.94647804,  -49.64400082,  -65.80546984]])

Methods

__call__(times)

Interpolate rotations.