python scripted_shapekey_keyframing.py

Posted 2021-05-09

import bpy
import bmesh
import numpy as np

## ------- part 1 --- do this once.
sig = 0.3
n_frames = 101
bpy.context.scene.frame_end = n_frames

pi = np.pi
make_ico = bpy.ops.mesh.primitive_ico_sphere_add
make_ico(subdivisions=3, size = 2.0, location = (0,0,3))
obj = bpy.context.active_object
me = obj.data

ico0 = np.array([v.co for v in me.vertices]) # get ico vertices
zmin, zmax = ico0[:,2].min(), ico0[:,2].max()
zc = np.linspace(zmin, zmax, n_frames)
ico = np.zeros_like(ico0)
data = []

for i in range(n_frames):
    ico[:,:2] = (1.0 + np.exp(-(ico0[:,2] - zc[i])**2/(2.*sig**2)))[:,None] * ico0[:,:2]
    ico[:,2] = ico0[:,2]
    data.append(ico.copy())


for i_frame in range(n_frames):
    block = obj.shape_key_add(name=str(i_frame), from_mix=False)  # returns a key_blocks member
    block.value = 1
    block.mute = True
    for (vert, co) in zip(block.data, data[i_frame]):
        vert.co = co

for i_frame in range(n_frames):
    DATA_PATH = obj.data.shape_keys.key_blocks[str(i_frame)].path_from_id('mute')

    block.mute = False
    exec(obj.keyframe_insert(data_path=DATA_PATH, frame = i_frame + 1, index=-1))

    block.mute = True
    exec(obj.keyframe_insert(data_path=DATA_PATH, frame = i_frame + 2, index=-1))