animation.py

from math import *

import random
import bpy


N_FLAPS = 30
N_SHAFTS = 42

SHAFTS = ["Circle.{:03d}".format(i) for i in range(N_SHAFTS)]

FRAMES_PER_IMAGE = 10
FRAMES_PER_PAUSE = 10

# The percentage of shafts to rotate in each iteration
SHAFTS_TO_ROTATE_PER_IT = 0.3
SHAFTS_TO_ROTATE_PER_IT_MIN = 0.1

N_ROTATIONS = 1


def clear_animation_data():
    for shaft in SHAFTS:
        obj = bpy.data.objects[shaft]
        obj.animation_data_clear()

def pin_to_current_frame(frame_count):
    for shaft in SHAFTS:
        obj = bpy.data.objects[shaft]
        obj.keyframe_insert(
            data_path="rotation_euler",
            frame=frame_count,
            index=1)

def rads(angle):
    return angle * pi / 180


clear_animation_data()

frame_count = 1

pin_to_current_frame(frame_count)

for _ in range(N_ROTATIONS):

    shafts_rotated = []

    while len(shafts_rotated) < N_SHAFTS:
        # The shafts that have not been rotated yet
        shafts_remaining = list(set(SHAFTS).difference(shafts_rotated))

        if len(shafts_remaining) <= N_SHAFTS * SHAFTS_TO_ROTATE_PER_IT_MIN:
            # There are too few shafts remaining. Rotate them all.
            n_shafts_to_rotate = len(shafts_remaining)

        else:
            # There are enough shafts remainig. Rotate a percentage of them.
            n_shafts_to_rotate = ceil(len(shafts_remaining) * SHAFTS_TO_ROTATE_PER_IT)

        shafts_to_rotate = random.sample(shafts_remaining, n_shafts_to_rotate)

        # Rotate the selected shafts
        for shaft in shafts_to_rotate:
            obj = bpy.data.objects[shaft]
            obj.rotation_euler.y -= rads(360 / Flaps)

        shafts_rotated += shafts_to_rotate

        frame_count += FRAMES_PER_DIGIT
        pin_to_current_frame(frame_count)

        frame_count += FRAMES_PER_PAUSE
        pin_to_current_frame(frame_count)

# Make everything linear instead of bezier
for shaft in SHAFTS:
    obj = bpy.data.objects[shaft]
    fcurves = obj.animation_data.action.fcurves
    for fcurve in fcurves:
        for kf in fcurve.keyframe_points:
            kf.interpolation = 'LINEAR'

# Adjust total frame count in this animation
bpy.data.scenes[0].frame_end = frame_count