Animating Blender properties

Setting a keyframe

Animating an object in Blender comes down to setting some keyframes to the properties of that object. The function set_keyframe() is designed for this purpose. In this example the location of a tetrahedron is animated:

import ddg
from ddg.visualization.blender.animation import set_keyframe
from ddg.datastructures.halfedge.surface_generator import tetrahedron

bobj = ddg.to_blender_object(tetrahedron())
fps = 24
set_keyframe(bobj, 0 * fps, "location", (0, 0, 0))
set_keyframe(bobj, 1 * fps, "location", (0, 0, 1))
set_keyframe(bobj, 2 * fps, "location", (0, 0, 0))

Additionaly, one can add animation to the rotation property of the tetrahedron in a similar way:

import numpy as np

set_keyframe(bobj, 0, "rotation_euler", (0, 0, 0))
set_keyframe(bobj, 2 * fps, "rotation_euler", (0, 0, 2 * np.pi))

Clearing the animation data

To clear the animation data that was set on the properties of an object, one can run:

from ddg.visualization.blender.animation import clear_animation_data

clear_animation_data(bobj)

Setting multiple keyframes at the same time

When the animation becomes more complex one might want to set the values of a property in multiple frames at the same time. Running this code block would have the same effect as the two first code blocks:

from ddg.visualization.blender.animation import animate_property

animate_property(
    bobj, "location", [i * fps for i in range(3)], [(0, 0, i % 2) for i in range(3)]
)
animate_property(
    bobj,
    "rotation_euler",
    [2 * i * fps for i in range(2)],
    [(0, 0, 2 * np.pi * (i % 2)) for i in range(2)],
)

For even more complex animations, one can set multiple frames to multiple properties. This code block sets the animation for the location and the scaling at the same time:

from ddg.visualization.blender.animation import animate_properties

clear_animation_data(bobj)
animate_properties(
    bobj,
    [i * fps for i in range(3)],
    {
        "location": [(0, 0, i % 2) for i in range(3)],
        "scale": [(1 + (i % 2), 1, 1) for i in range(3)],
    },
)