Blender Script: Convert Character Animation to In-Place (Zero Root Bone Translation)

make_animation_in_place.py

import bpy

def make_animation_in_place(anim_name="rotate"):
    """
    Modifies the given animation to be in-place by setting
    X, Y, and Z location keyframe values to 0.
    """
    action = bpy.data.actions.get(anim_name)

    if not action:
        print(f"Animation '{anim_name}' not found.")
        return

    print(f"Processing animation: {action.name}")

    # We are interested in location F-Curves.
    # For an object, these are typically:
    # - 'location' with array_index 0 (X)
    # - 'location' with array_index 1 (Y)
    # - 'location' with array_index 2 (Z)
    # Or, if applied to bones in pose mode:
    # - 'pose.bones["BoneName"].location' with array_index 0 (X), 1 (Y), 2 (Z)

    fcurves_modified_count = 0

    for fcurve in action.fcurves:
        # Check for object-level location
        if fcurve.data_path == "location" and fcurve.array_index in [0, 1, 2]:
            print(f"  Modifying F-Curve: {fcurve.data_path}, Index: {fcurve.array_index}")
            for keyframe in fcurve.keyframe_points:
                keyframe.co.y = 0.0  # Set value to 0
                keyframe.handle_left.y = 0.0
                keyframe.handle_right.y = 0.0
            fcurves_modified_count += 1
        # Check for bone-level location (common for armatures)
        elif ".location" in fcurve.data_path and fcurve.array_index in [0, 1, 2]:
             # Make sure it's a pose bone location, not something else
            if fcurve.data_path.startswith("pose.bones[") and fcurve.data_path.endswith("].location"):
                print(f"  Modifying F-Curve: {fcurve.data_path}, Index: {fcurve.array_index}")
                for keyframe in fcurve.keyframe_points:
                    keyframe.co.y = 0.0  # Set value to 0
                    keyframe.handle_left.y = 0.0
                    keyframe.handle_right.y = 0.0
                fcurves_modified_count += 1

    if fcurves_modified_count > 0:
        print(f"Successfully modified {fcurves_modified_count} F-Curves for in-place animation.")
        # It's good practice to update the view
        for area in bpy.context.screen.areas:
            if area.type == 'GRAPH_EDITOR':
                area.tag_redraw()
            elif area.type == 'DOPESHEET_EDITOR':
                area.tag_redraw()
    else:
        print(f"No location F-Curves found or modified for animation '{anim_name}'. Ensure the animation has location keyframes.")

# --- How to use ---
# 1. Open Blender.
# 2. Go to the "Scripting" tab.
# 3. Click "+ New" to create a new text block.
# 4. Paste this script into the text editor.
# 5. Make sure the object with the "rotate" animation is selected,
#    OR that the animation is available in bpy.data.actions.
# 6. Change anim_name="rotate" if your animation has a different name.
# 7. Click "Run Script" (the play button).

# Example of how to run it, REPLACE WITH YOUR ANIMATION NAME:
make_animation_in_place(anim_name="rotate")

print("Script finished.")