Keyframes Spline Interpolator

Tutorial on making keyframe-based animation in FURY using Spline interpolators.

import numpy as np

import fury

scene = fury.window.Scene()

showm = fury.window.ShowManager(
    scene=scene, size=(900, 768), reset_camera=False, order_transparent=True
)

Position keyframes as a dict object containing timestamps as keys and positions as values.

position_keyframes = {
    0.0: np.array([0, 0, 0]),
    2.0: np.array([10, 3, 5]),
    4.0: np.array([20, 14, 13]),
    6.0: np.array([-20, 20, 0]),
    8.0: np.array([17, -10, 15]),
    10.0: np.array([0, -6, 0]),
}

creating FURY dots to visualize the position values.

pos_dots = fury.actor.dot(np.array(list(position_keyframes.values())))

creating two timelines (one uses linear and the other uses’ spline interpolator), each timeline controls a sphere actor

sphere_linear = fury.actor.sphere(np.array([[0, 0, 0]]), (1, 0.5, 0.2), radii=0.5)

linear_anim = fury.animation.Animation()
linear_anim.add_actor(sphere_linear)

linear_anim.set_position_keyframes(position_keyframes)

Note: linear_interpolator is used by default. So, no need to set it for this first animation that we need to linearly interpolate positional animation.

creating a second timeline that translates another larger sphere actor using spline interpolator.

sphere_spline = fury.actor.sphere(np.array([[0, 0, 0]]), (0.3, 0.9, 0.6), radii=1)
spline_anim = fury.animation.Animation(actors=sphere_spline)
spline_anim.set_position_keyframes(position_keyframes)

Setting 5th degree spline interpolator for position keyframes.

spline_anim.set_position_interpolator(fury.animation.spline_interpolator, degree=5)

Wrapping animations up!

Adding everything to a Timeline to control the two timelines.

First we create a timeline with a playback panel:

timeline = fury.animation.Timeline(playback_panel=True)

Add visualization dots actor to the scene.

scene.add(pos_dots)

Adding the animations to the timeline (so that it controls their playback).

timeline.add_animation([linear_anim, spline_anim])

Adding the timeline to the show manager.

showm.add_animation(timeline)

Now that these two animations are added to timeline, if the timeline is played, paused, …, all these changes will reflect on the animations.

interactive = False

if interactive:
    showm.start()

fury.window.record(
    scene=scene, out_path="viz_keyframe_animation_spline.png", size=(900, 768)
)