def append_and_blend()

in fairmotion/ops/motion.py [0:0]

• 44 lines of code
• 9 McCabe index (conditional complexity)

def append_and_blend(motion1, motion2, blend_length=0):
    assert isinstance(motion1, motion_class.Motion)
    assert isinstance(motion2, motion_class.Motion)
    assert motion1.skel.num_joints() == motion2.skel.num_joints()

    combined_motion = copy.deepcopy(motion1)
    combined_motion.name = f"{motion1.name}+{motion2.name}"

    if motion1.num_frames() == 0:
        for i in range(motion2.num_frames()):
            combined_motion.poses.append(motion2.poses[i])
            if hasattr(motion1, "velocities"):
                combined_motion.velocities.append(motion2.velocities[i])
        return combined_motion

    frame_target = motion2.time_to_frame(blend_length)
    frame_source = motion1.time_to_frame(motion1.length() - blend_length)

    # Translate and rotate motion2 to location of frame_source
    pose1 = motion1.get_pose_by_frame(frame_source)
    pose2 = motion2.get_pose_by_frame(0)

    R1, p1 = conversions.T2Rp(pose1.get_root_transform())
    R2, p2 = conversions.T2Rp(pose2.get_root_transform())

    # Translation to be applied
    dp = p1 - p2
    dp = dp - math.projectionOnVector(dp, motion1.skel.v_up_env)
    axis = motion1.skel.v_up_env

    # Rotation to be applied
    Q1 = conversions.R2Q(R1)
    Q2 = conversions.R2Q(R2)
    _, theta = quaternion.Q_closest(Q1, Q2, axis)
    dR = conversions.A2R(axis * theta)

    motion2 = translate(motion2, dp)
    motion2 = rotate(motion2, dR)

    t_total = motion1.fps * frame_source
    t_processed = 0.0
    poses_new = []
    for i in range(motion2.num_frames()):
        dt = 1 / motion2.fps
        t_total += dt
        t_processed += dt
        pose_target = motion2.get_pose_by_frame(i)
        # Blend pose for a moment
        if t_processed <= blend_length:
            alpha = t_processed / float(blend_length)
            pose_source = motion1.get_pose_by_time(t_total)
            pose_target = blend(pose_source, pose_target, alpha)
        poses_new.append(pose_target)

    del combined_motion.poses[frame_source + 1 :]
    for i in range(len(poses_new)):
        combined_motion.add_one_frame(copy.deepcopy(poses_new[i].data))

    return combined_motion