blender/release/scripts/modules/bpy_extras/anim_utils.py

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# <pep8-80 compliant>

__all__ = (
    "bake_action",
    )

import bpy


def bake_action(frame_start,
                frame_end,
                frame_step=1,
                only_selected=False,
                do_pose=True,
                do_object=True,
                do_constraint_clear=False,
                do_clean=False,
                action=None,
                ):

    """
    Return an image from the file path with options to search multiple paths
    and return a placeholder if its not found.

    :arg frame_start: First frame to bake.
    :type frame_start: int
    :arg frame_end: Last frame to bake.
    :type frame_end: int
    :arg frame_step: Frame step.
    :type frame_step: int
    :arg only_selected: Only bake selected data.
    :type only_selected: bool
    :arg do_pose: Bake pose channels.
    :type do_pose: bool
    :arg do_object: Bake objects.
    :type do_object: bool
    :arg do_constraint_clear: Remove constraints.
    :type do_constraint_clear: bool
    :arg do_clean: Remove redundant keyframes after baking.
    :type do_clean: bool
    :arg action: An action to bake the data into, or None for a new action
       to be created.
    :type action: :class:`bpy.types.Action` or None

    :return: an action or None
    :rtype: :class:`bpy.types.Action`
    """

    # -------------------------------------------------------------------------
    # Helper Functions

    def pose_frame_info(obj):
        from mathutils import Matrix

        info = {}

        pose = obj.pose

        pose_items = pose.bones.items()

        for name, pbone in pose_items:
            binfo = {}
            bone = pbone.bone

            binfo["parent"] = getattr(bone.parent, "name", None)
            binfo["bone"] = bone
            binfo["pbone"] = pbone
            binfo["matrix_local"] = bone.matrix_local.copy()
            try:
                binfo["matrix_local_inv"] = binfo["matrix_local"].inverted()
            except:
                binfo["matrix_local_inv"] = Matrix()

            binfo["matrix"] = bone.matrix.copy()
            binfo["matrix_pose"] = pbone.matrix.copy()
            try:
                binfo["matrix_pose_inv"] = binfo["matrix_pose"].inverted()
            except:
                binfo["matrix_pose_inv"] = Matrix()

            info[name] = binfo

        for name, pbone in pose_items:
            binfo = info[name]
            binfo_parent = binfo.get("parent", None)
            if binfo_parent:
                binfo_parent = info[binfo_parent]

            matrix = binfo["matrix_pose"]
            rest_matrix = binfo["matrix_local"]

            if binfo_parent:
                matrix = binfo_parent["matrix_pose_inv"] * matrix
                rest_matrix = binfo_parent["matrix_local_inv"] * rest_matrix

            binfo["matrix_key"] = rest_matrix.inverted() * matrix

        return info

    def obj_frame_info(obj):
        info = {}
        # parent = obj.parent
        info["matrix_key"] = obj.matrix_local.copy()
        return info

    # -------------------------------------------------------------------------
    # Setup the Context

    # TODO, pass data rather then grabbing from the context!
    scene = bpy.context.scene
    obj = bpy.context.object
    pose = obj.pose
    frame_back = scene.frame_current

    if pose is None:
        do_pose = False

    if do_pose is None and do_object is None:
        return None

    pose_info = []
    obj_info = []

    frame_range = range(frame_start, frame_end + 1, frame_step)

    # -------------------------------------------------------------------------
    # Collect transformations

    # could speed this up by applying steps here too...
    for f in frame_range:
        scene.frame_set(f)

        if do_pose:
            pose_info.append(pose_frame_info(obj))
        if do_object:
            obj_info.append(obj_frame_info(obj))

        f += 1

    # -------------------------------------------------------------------------
    # Create action

    # in case animation data hasn't been created
    atd = obj.animation_data_create()
    if action is None:
        action = bpy.data.actions.new("Action")
    atd.action = action

    if do_pose:
        pose_items = pose.bones.items()
    else:
        pose_items = []  # skip

    # -------------------------------------------------------------------------
    # Apply transformations to action

    # pose
    for name, pbone in (pose_items if do_pose else ()):
        if only_selected and not pbone.bone.select:
            continue

        if do_constraint_clear:
            while pbone.constraints:
                pbone.constraints.remove(pbone.constraints[0])

        for f in frame_range:
            f_step = (f - frame_start) // frame_step
            matrix = pose_info[f_step][name]["matrix_key"]

            # pbone.location = matrix.to_translation()
            # pbone.rotation_quaternion = matrix.to_quaternion()
            pbone.matrix_basis = matrix

            pbone.keyframe_insert("location", -1, f, name)

            rotation_mode = pbone.rotation_mode

            if rotation_mode == 'QUATERNION':
                pbone.keyframe_insert("rotation_quaternion", -1, f, name)
            elif rotation_mode == 'AXIS_ANGLE':
                pbone.keyframe_insert("rotation_axis_angle", -1, f, name)
            else:  # euler, XYZ, ZXY etc
                pbone.keyframe_insert("rotation_euler", -1, f, name)

            pbone.keyframe_insert("scale", -1, f, name)

    # object. TODO. multiple objects
    if do_object:
        if do_constraint_clear:
            while obj.constraints:
                obj.constraints.remove(obj.constraints[0])

        for f in frame_range:
            matrix = obj_info[(f - frame_start) // frame_step]["matrix_key"]
            obj.matrix_local = matrix

            obj.keyframe_insert("location", -1, f)

            rotation_mode = obj.rotation_mode

            if rotation_mode == 'QUATERNION':
                obj.keyframe_insert("rotation_quaternion", -1, f)
            elif rotation_mode == 'AXIS_ANGLE':
                obj.keyframe_insert("rotation_axis_angle", -1, f)
            else:  # euler, XYZ, ZXY etc
                obj.keyframe_insert("rotation_euler", -1, f)

            obj.keyframe_insert("scale", -1, f)

    scene.frame_set(frame_back)

    # -------------------------------------------------------------------------
    # Clean

    if do_clean:
        for fcu in action.fcurves:
            keyframe_points = fcu.keyframe_points
            i = 1
            while i < len(fcu.keyframe_points) - 1:
                val_prev = keyframe_points[i - 1].co[1]
                val_next = keyframe_points[i + 1].co[1]
                val = keyframe_points[i].co[1]

                if abs(val - val_prev) + abs(val - val_next) < 0.0001:
                    keyframe_points.remove(keyframe_points[i])
                else:
                    i += 1

    return action