Blender Python: Animate Selected Image Planes

bpy_animate_planes_as_sequence.py

# Script written by SuperFromND. CC0. Do whatever you want!
# Written for Blender 4.2.3 LTS, but should work in older versions just fine.

# This script takes the selected objects (assumed to be image planes stacked on top of eachother)
# and generates keyframe data such that each object will "animate" by being scaled up and down
# for a set duration in sequence. This effectively emulates an image sequence/animation.

# This script was designed mainly for stage creators and 3D modelling work for the Ikemen GO fighting game engine.
# This is because we use the glTF format, which doesn't support animated textures of any kind.

# ==================================================================================================================
# SETTINGS START HERE

# Change this number to set the duration of every frame.
# The framerate is tied to whatever the Blender project's framerate is; by default, 24 FPS.
frame_length = 1

# SETTINGS END HERE; the rest is program code. Don't touch unless you know what you're doing!
# ==================================================================================================================
import bpy

frame_start = 0
animation_length = frame_length * len(bpy.context.selected_objects)

scale_off = (0.0, 0.0, 1.0)
scale_on  = (1.0, 1.0, 1.0)

for obj in bpy.context.selected_objects:
    frame_end = frame_start + frame_length
    
    # Hides the object at the start of the animation
    # Ensures a proper cyclic loop point
    if frame_start != 0:
        obj.scale = scale_off
        obj.keyframe_insert(data_path="scale", frame=0)
    
    # Shows the object
    obj.scale = scale_on
    obj.keyframe_insert(data_path="scale", frame=frame_start)
    
    # Hides the object
    obj.scale = scale_off
    obj.keyframe_insert(data_path="scale", frame=frame_end)
    
    # Similar to above, but for the end point
    if frame_end != animation_length:
        obj.scale = scale_off
        obj.keyframe_insert(data_path="scale", frame=animation_length)
        
    # Oh, and for the first object, show it on the end of animation too
    # This just prevents loop flickering
    if frame_start == 0:
        obj.scale = scale_on
        obj.keyframe_insert(data_path="scale", frame=animation_length)
    
    # Sets animation curves to CONSTANT and enables cyclic curves
    fcurves = obj.animation_data.action.fcurves
    for fcurve in fcurves:
        c = fcurve.modifiers.new('CYCLES')
        fcurve.extrapolation = 'CONSTANT'
        for kf in fcurve.keyframe_points:
            kf.interpolation = 'CONSTANT'
    
    # Increment frame start
    frame_start += frame_length