Keyframe animation: Camera and opacity

Camera and opacity keyframe animation explained in this tutorial.

import numpy as np

import fury
from fury.animation import Animation, CameraAnimation, Timeline
from fury.animation.interpolator import cubic_spline_interpolator
from fury.data import fetch_viz_cubemaps, read_viz_cubemap
from fury.io import load_cube_map_texture

The Plan

The plan here is to animate, scale, and translate 50 spheres randomly, then show FURY text at the end.

Let’s fetch and load a skybox texture.

fetch_viz_cubemaps()
texture_files = read_viz_cubemap("skybox")
cube_map = load_cube_map_texture(texture_files)

scene = fury.window.Scene(skybox=cube_map)

showm = fury.window.ShowManager(
    scene=scene,
    size=(900, 768),
    pixel_ratio=2,
)

Creating the main Timeline

Here we create a Timeline so that it can control all animations from one place. A playback panel is attached to provide interactive playback controls.

timeline = Timeline(playback_panel=True, loop=True)

Creating an actor for visualization.

plane = fury.actor.box(
    np.array([[0, 0, 0]]),
    colors=np.array([[1, 1, 1]]),
    scales=np.array([[20, 0.2, 20]]),
)

Creating FURY text

fury_text = fury.actor.text(
    text="FURY", position=(0, 15, 0), font_size=5, anchor="middle-center"
)

Creating an Animation to animate the opacity of fury_text.

text_anim = Animation(actors=fury_text, loop=False)

Opacity is set to 0 at time 29 and to 1 at time 35. Linear interpolation is used by default.

text_anim.set_opacity(29, 0.0)
text_anim.set_opacity(35, 1.0)
timeline.add_animation(text_anim)

Creating and animating 50 spheres

for _ in range(50):
    ###########################################################################
    # Create a sphere actor centered at the origin with random color and radius.
    sphere_actor = fury.actor.sphere(
        np.array([[0, 0, 0]]),
        colors=np.random.random([1, 3]),
        radii=np.random.random(1) * 0.5 + 0.1,
    )

    ###########################################################################
    # Create one animation for this sphere.
    animation = Animation(actors=sphere_actor)

    ###########################################################################
    # Generate random position and scale values every two seconds.
    for t in range(0, 50, 2):
        animation.set_position(t, np.random.random(3) * 30 - np.array([15, 0, 15]))
        animation.set_scale(t, np.repeat(np.random.random(1), 3))

    ###########################################################################
    # Change the position interpolator to cubic spline interpolation.
    animation.set_position_interpolator(cubic_spline_interpolator)
    timeline.add_animation(animation)

Animating the camera

Camera animations are represented with CameraAnimation. Three properties can control the camera: position, focal position, and view-up direction.

camera_anim = CameraAnimation(loop=False)
timeline.add_animation(camera_anim)

camera_positions = {
    0: np.array([3, 3, 3]),
    4: np.array([50, 25, -40]),
    7: np.array([-50, 50, -40]),
    10: np.array([-25, 25, 20]),
    14: np.array([0, 16, 25]),
    20: np.array([0, 14.5, 20]),
}

camera_focal_positions = {
    15: np.array([0, 0, 0]),
    20: np.array([3, 9, 5]),
    23: np.array([7, 5, 3]),
    25: np.array([-2, 9, -6]),
    27: np.array([0, 16, 0]),
    31: np.array([0, 14.5, 0]),
}

camera_anim.set_position_keyframes(camera_positions)
camera_anim.set_focal_keyframes(camera_focal_positions)

Change camera position and focal interpolators.

camera_anim.set_position_interpolator(cubic_spline_interpolator)
camera_anim.set_focal_interpolator(cubic_spline_interpolator)

Add non-animated actors to the scene.

scene.add(plane)

Add the timeline to the ShowManager for interactive playback.

showm.add_animation(timeline)

The ShowManager must go on!

showm.start()