import_fbx.py

# ##### BEGIN GPL LICENSE BLOCK #####
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# ##### END GPL LICENSE BLOCK #####

# <pep8 compliant>

# Script copyright (C) Blender Foundation

# FBX 7.1.0 -> 7.4.0 loader for Blender

# Not totally pep8 compliant.
#   pep8 import_fbx.py --ignore=E501,E123,E702,E125

if "bpy" in locals():
    import importlib
    if "parse_fbx" in locals():
        importlib.reload(parse_fbx)
    if "fbx_utils" in locals():
        importlib.reload(fbx_utils)

import bpy

# -----
# Utils
from . import parse_fbx, fbx_utils

from .parse_fbx import data_types, FBXElem
from .fbx_utils import (
    units_convertor_iter,
    array_to_matrix4,
    similar_values,
    similar_values_iter,
    FBXImportSettings
)

# global singleton, assign on execution
fbx_elem_nil = None

# Units convertors...
convert_deg_to_rad_iter = units_convertor_iter("degree", "radian")

MAT_CONVERT_BONE = fbx_utils.MAT_CONVERT_BONE.inverted()
MAT_CONVERT_LAMP = fbx_utils.MAT_CONVERT_LAMP.inverted()
MAT_CONVERT_CAMERA = fbx_utils.MAT_CONVERT_CAMERA.inverted()


def elem_find_first(elem, id_search, default=None):
    for fbx_item in elem.elems:
        if fbx_item.id == id_search:
            return fbx_item
    return default


def elem_find_iter(elem, id_search):
    for fbx_item in elem.elems:
        if fbx_item.id == id_search:
            yield fbx_item


def elem_find_first_string(elem, id_search):
    fbx_item = elem_find_first(elem, id_search)
    if fbx_item is not None:
        assert(len(fbx_item.props) == 1)
        assert(fbx_item.props_type[0] == data_types.STRING)
        return fbx_item.props[0].decode('utf-8')
    return None


def elem_find_first_bytes(elem, id_search, decode=True):
    fbx_item = elem_find_first(elem, id_search)
    if fbx_item is not None:
        assert(len(fbx_item.props) == 1)
        assert(fbx_item.props_type[0] == data_types.STRING)
        return fbx_item.props[0]
    return None


def elem_repr(elem):
    return "%s: props[%d=%r], elems=(%r)" % (
        elem.id,
        len(elem.props),
        ", ".join([repr(p) for p in elem.props]),
        # elem.props_type,
        b", ".join([e.id for e in elem.elems]),
        )


def elem_split_name_class(elem):
    assert(elem.props_type[-2] == data_types.STRING)
    elem_name, elem_class = elem.props[-2].split(b'\x00\x01')
    return elem_name, elem_class


def elem_name_ensure_class(elem, clss=...):
    elem_name, elem_class = elem_split_name_class(elem)
    if clss is not ...:
        assert(elem_class == clss)
    return elem_name.decode('utf-8')


def elem_split_name_class_nodeattr(elem):
    assert(elem.props_type[-2] == data_types.STRING)
    elem_name, elem_class = elem.props[-2].split(b'\x00\x01')
    assert(elem_class == b'NodeAttribute')
    assert(elem.props_type[-1] == data_types.STRING)
    elem_class = elem.props[-1]
    return elem_name, elem_class


def elem_uuid(elem):
    assert(elem.props_type[0] == data_types.INT64)
    return elem.props[0]


def elem_prop_first(elem, default=None):
    return elem.props[0] if (elem is not None) and elem.props else default


# ----
# Support for
# Properties70: { ... P:
def elem_props_find_first(elem, elem_prop_id):

    # support for templates (tuple of elems)
    if type(elem) is not FBXElem:
        assert(type(elem) is tuple)
        for e in elem:
            result = elem_props_find_first(e, elem_prop_id)
            if result is not None:
                return result
        assert(len(elem) > 0)
        return None

    for subelem in elem.elems:
        assert(subelem.id == b'P')
        if subelem.props[0] == elem_prop_id:
            return subelem
    return None


def elem_props_get_color_rgb(elem, elem_prop_id, default=None):
    elem_prop = elem_props_find_first(elem, elem_prop_id)
    if elem_prop is not None:
        assert(elem_prop.props[0] == elem_prop_id)
        if elem_prop.props[1] == b'Color':
            # FBX version 7300
            assert(elem_prop.props[1] == b'Color')
            assert(elem_prop.props[2] == b'')
            assert(elem_prop.props[3] in {b'A', b'A+', b'AU'})
        else:
            assert(elem_prop.props[1] == b'ColorRGB')
            assert(elem_prop.props[2] == b'Color')
        assert(elem_prop.props_type[4:7] == bytes((data_types.FLOAT64,)) * 3)
        return elem_prop.props[4:7]
    return default


def elem_props_get_vector_3d(elem, elem_prop_id, default=None):
    elem_prop = elem_props_find_first(elem, elem_prop_id)
    if elem_prop is not None:
        assert(elem_prop.props_type[4:7] == bytes((data_types.FLOAT64,)) * 3)
        return elem_prop.props[4:7]
    return default


def elem_props_get_number(elem, elem_prop_id, default=None):
    elem_prop = elem_props_find_first(elem, elem_prop_id)
    if elem_prop is not None:
        assert(elem_prop.props[0] == elem_prop_id)
        if elem_prop.props[1] == b'double':
            assert(elem_prop.props[1] == b'double')
            assert(elem_prop.props[2] == b'Number')
        else:
            assert(elem_prop.props[1] == b'Number')
            assert(elem_prop.props[2] == b'')
            assert(elem_prop.props[3] in {b'A', b'A+', b'AU'})

        # we could allow other number types
        assert(elem_prop.props_type[4] == data_types.FLOAT64)

        return elem_prop.props[4]
    return default


def elem_props_get_integer(elem, elem_prop_id, default=None):
    elem_prop = elem_props_find_first(elem, elem_prop_id)
    if elem_prop is not None:
        assert(elem_prop.props[0] == elem_prop_id)
        if elem_prop.props[1] == b'int':
            assert(elem_prop.props[1] == b'int')
            assert(elem_prop.props[2] == b'Integer')
        elif elem_prop.props[1] == b'ULongLong':
            assert(elem_prop.props[1] == b'ULongLong')
            assert(elem_prop.props[2] == b'')

        # we could allow other number types
        assert(elem_prop.props_type[4] in {data_types.INT32, data_types.INT64})

        return elem_prop.props[4]
    return default


def elem_props_get_bool(elem, elem_prop_id, default=None):
    elem_prop = elem_props_find_first(elem, elem_prop_id)
    if elem_prop is not None:
        assert(elem_prop.props[0] == elem_prop_id)
        assert(elem_prop.props[1] == b'bool')
        assert(elem_prop.props[2] == b'')
        assert(elem_prop.props[3] == b'')

        # we could allow other number types
        assert(elem_prop.props_type[4] == data_types.INT32)
        assert(elem_prop.props[4] in {0, 1})

        return bool(elem_prop.props[4])
    return default


def elem_props_get_enum(elem, elem_prop_id, default=None):
    elem_prop = elem_props_find_first(elem, elem_prop_id)
    if elem_prop is not None:
        assert(elem_prop.props[0] == elem_prop_id)
        assert(elem_prop.props[1] == b'enum')
        assert(elem_prop.props[2] == b'')
        assert(elem_prop.props[3] == b'')

        # we could allow other number types
        assert(elem_prop.props_type[4] == data_types.INT32)

        return elem_prop.props[4]
    return default


def elem_props_get_visibility(elem, elem_prop_id, default=None):
    elem_prop = elem_props_find_first(elem, elem_prop_id)
    if elem_prop is not None:
        assert(elem_prop.props[0] == elem_prop_id)
        assert(elem_prop.props[1] == b'Visibility')
        assert(elem_prop.props[2] == b'')
        assert(elem_prop.props[3] in {b'A', b'A+', b'AU'})

        # we could allow other number types
        assert(elem_prop.props_type[4] == data_types.FLOAT64)

        return elem_prop.props[4]
    return default


# ----------------------------------------------------------------------------
# Blender

# ------
# Object
from collections import namedtuple


FBXTransformData = namedtuple("FBXTransformData", (
    "loc",
    "rot", "rot_ofs", "rot_piv", "pre_rot", "pst_rot", "rot_ord", "rot_alt_mat",
    "sca", "sca_ofs", "sca_piv",
))


def blen_read_custom_properties(fbx_obj, blen_obj, settings):
    # There doesn't seem to be a way to put user properties into templates, so this only get the object properties:
    fbx_obj_props = elem_find_first(fbx_obj, b'Properties70')
    if fbx_obj_props:
        for fbx_prop in fbx_obj_props.elems:
            assert(fbx_prop.id == b'P')

            if b'U' in fbx_prop.props[3]:
                if fbx_prop.props[0] == b'UDP3DSMAX':
                    # Special case for 3DS Max user properties:
                    assert(fbx_prop.props[1] == b'KString')
                    assert(fbx_prop.props_type[4] == data_types.STRING)
                    items = fbx_prop.props[4].decode('utf-8')
                    for item in items.split('\r\n'):
                        if item:
                            prop_name, prop_value = item.split('=', 1)
                            blen_obj[prop_name.strip()] = prop_value.strip()
                else:
                    prop_name = fbx_prop.props[0].decode('utf-8')
                    prop_type = fbx_prop.props[1]
                    if prop_type in {b'Vector', b'Vector3D', b'Color', b'ColorRGB'}:
                        assert(fbx_prop.props_type[4:7] == bytes((data_types.FLOAT64,)) * 3)
                        blen_obj[prop_name] = fbx_prop.props[4:7]
                    elif prop_type in {b'Vector4', b'ColorRGBA'}:
                        assert(fbx_prop.props_type[4:8] == bytes((data_types.FLOAT64,)) * 4)
                        blen_obj[prop_name] = fbx_prop.props[4:8]
                    elif prop_type == b'Vector2D':
                        assert(fbx_prop.props_type[4:6] == bytes((data_types.FLOAT64,)) * 2)
                        blen_obj[prop_name] = fbx_prop.props[4:6]
                    elif prop_type in {b'Integer', b'int'}:
                        assert(fbx_prop.props_type[4] == data_types.INT32)
                        blen_obj[prop_name] = fbx_prop.props[4]
                    elif prop_type == b'KString':
                        assert(fbx_prop.props_type[4] == data_types.STRING)
                        blen_obj[prop_name] = fbx_prop.props[4].decode('utf-8')
                    elif prop_type in {b'Number', b'double', b'Double'}:
                        assert(fbx_prop.props_type[4] == data_types.FLOAT64)
                        blen_obj[prop_name] = fbx_prop.props[4]
                    elif prop_type in {b'Float', b'float'}:
                        assert(fbx_prop.props_type[4] == data_types.FLOAT32)
                        blen_obj[prop_name] = fbx_prop.props[4]
                    elif prop_type in {b'Bool', b'bool'}:
                        assert(fbx_prop.props_type[4] == data_types.INT32)
                        blen_obj[prop_name] = fbx_prop.props[4] != 0
                    elif prop_type in {b'Enum', b'enum'}:
                        assert(fbx_prop.props_type[4:6] == bytes((data_types.INT32, data_types.STRING)))
                        val = fbx_prop.props[4]
                        if settings.use_custom_props_enum_as_string:
                            enum_items = fbx_prop.props[5].decode('utf-8').split('~')
                            assert(val >= 0 and val < len(enum_items))
                            blen_obj[prop_name] = enum_items[val]
                        else:
                            blen_obj[prop_name] = val
                    else:
                        print ("WARNING: User property type '%s' is not supported" % prop_type.decode('utf-8'))


def blen_read_object_transform_do(transform_data):
    from mathutils import Matrix, Euler

    # translation
    lcl_translation = Matrix.Translation(transform_data.loc)

    # rotation
    to_rot = lambda rot, rot_ord: Euler(convert_deg_to_rad_iter(rot), rot_ord).to_matrix().to_4x4()
    lcl_rot = to_rot(transform_data.rot, transform_data.rot_ord) * transform_data.rot_alt_mat
    pre_rot = to_rot(transform_data.pre_rot, transform_data.rot_ord)
    pst_rot = to_rot(transform_data.pst_rot, transform_data.rot_ord)

    rot_ofs = Matrix.Translation(transform_data.rot_ofs)
    rot_piv = Matrix.Translation(transform_data.rot_piv)
    sca_ofs = Matrix.Translation(transform_data.sca_ofs)
    sca_piv = Matrix.Translation(transform_data.sca_piv)

    # scale
    lcl_scale = Matrix()
    lcl_scale[0][0], lcl_scale[1][1], lcl_scale[2][2] = transform_data.sca

    return (
        lcl_translation *
        rot_ofs *
        rot_piv *
        pre_rot *
        lcl_rot *
        pst_rot *
        rot_piv.inverted() *
        sca_ofs *
        sca_piv *
        lcl_scale *
        sca_piv.inverted()
    )


# XXX This might be weak, now that we can add vgroups from both bones and shapes, name collisions become
#     more likely, will have to make this more robust!!!
def add_vgroup_to_objects(vg_indices, vg_weights, vg_name, objects):
    assert(len(vg_indices) == len(vg_weights))
    if vg_indices:
        for obj in objects:
            # We replace/override here...
            vg = obj.vertex_groups.get(vg_name)
            if vg is None:
                vg = obj.vertex_groups.new(vg_name)
            for i, w in zip(vg_indices, vg_weights):
                vg.add((i,), w, 'REPLACE')


def blen_read_object_transform_preprocess(fbx_props, fbx_obj, rot_alt_mat):
    # This is quite involved, 'fbxRNode.cpp' from openscenegraph used as a reference
    const_vector_zero_3d = 0.0, 0.0, 0.0
    const_vector_one_3d = 1.0, 1.0, 1.0

    loc = list(elem_props_get_vector_3d(fbx_props, b'Lcl Translation', const_vector_zero_3d))
    rot = list(elem_props_get_vector_3d(fbx_props, b'Lcl Rotation', const_vector_zero_3d))
    sca = list(elem_props_get_vector_3d(fbx_props, b'Lcl Scaling', const_vector_one_3d))

    rot_ofs = elem_props_get_vector_3d(fbx_props, b'RotationOffset', const_vector_zero_3d)
    rot_piv = elem_props_get_vector_3d(fbx_props, b'RotationPivot', const_vector_zero_3d)
    sca_ofs = elem_props_get_vector_3d(fbx_props, b'ScalingOffset', const_vector_zero_3d)
    sca_piv = elem_props_get_vector_3d(fbx_props, b'ScalingPivot', const_vector_zero_3d)

    is_rot_act = elem_props_get_bool(fbx_props, b'RotationActive', False)

    if is_rot_act:
        pre_rot = elem_props_get_vector_3d(fbx_props, b'PreRotation', const_vector_zero_3d)
        pst_rot = elem_props_get_vector_3d(fbx_props, b'PostRotation', const_vector_zero_3d)
        rot_ord = {
            0: 'XYZ',
            1: 'XYZ',
            2: 'XZY',
            3: 'YZX',
            4: 'YXZ',
            5: 'ZXY',
            6: 'ZYX',
            }.get(elem_props_get_enum(fbx_props, b'RotationOrder', 0))
    else:
        pre_rot = const_vector_zero_3d
        pst_rot = const_vector_zero_3d
        rot_ord = 'XYZ'

    return FBXTransformData(loc,
                            rot, rot_ofs, rot_piv, pre_rot, pst_rot, rot_ord, rot_alt_mat,
                            sca, sca_ofs, sca_piv)


def blen_read_object(fbx_tmpl, fbx_obj, object_data, settings):
    elem_name_utf8 = elem_name_ensure_class(fbx_obj)

    # Object data must be created already
    obj = bpy.data.objects.new(name=elem_name_utf8, object_data=object_data)
    object_tdata_cache = settings.object_tdata_cache

    fbx_props = (elem_find_first(fbx_obj, b'Properties70'),
                 elem_find_first(fbx_tmpl, b'Properties70', fbx_elem_nil))
    assert(fbx_props[0] is not None)

    # ----
    # Misc Attributes

    obj.color[0:3] = elem_props_get_color_rgb(fbx_props, b'Color', (0.8, 0.8, 0.8))
    obj.hide = not bool(elem_props_get_visibility(fbx_props, b'Visibility', 1.0))

    # ----
    # Transformation

    from mathutils import Matrix
    from math import pi

    # rotation corrections
    if obj.type == 'CAMERA':
        rot_alt_mat = MAT_CONVERT_CAMERA
    elif obj.type == 'LAMP':
        rot_alt_mat = MAT_CONVERT_LAMP
    else:
        rot_alt_mat = Matrix()

    transform_data = object_tdata_cache.get(obj)
    if transform_data is None:
        transform_data = blen_read_object_transform_preprocess(fbx_props, fbx_obj, rot_alt_mat)
        object_tdata_cache[obj] = transform_data
    obj.matrix_basis = blen_read_object_transform_do(transform_data)

    if settings.use_custom_props:
        blen_read_custom_properties(fbx_obj, obj, settings)

    return obj


# --------
# Armature

def blen_read_armatures_add_bone(bl_obj, bl_arm, bones, b_uuid, matrices, fbx_tmpl_model):
    from mathutils import Matrix, Vector

    b_item, bsize, p_uuid, clusters = bones[b_uuid]
    fbx_bdata, bl_bname = b_item
    if bl_bname is not None:
        return bl_arm.edit_bones[bl_bname]  # Have already been created...

    p_ebo = None
    if p_uuid is not None:
        # Recurse over parents!
        p_ebo = blen_read_armatures_add_bone(bl_obj, bl_arm, bones, p_uuid, matrices, fbx_tmpl_model)

    if clusters:
        # Note in some cases, one bone can have several clusters (kind of LoD?), in Blender we'll always
        # use only the first, for now.
        fbx_cdata, meshes, objects = clusters[0]
        objects = {blen_o for fbx_o, blen_o in objects}

        # We assume matrices in cluster are rest pose of bones (they are in Global space!).
        # TransformLink is matrix of bone, in global space.
        # TransformAssociateModel is matrix of armature, in global space (at bind time).
        elm = elem_find_first(fbx_cdata, b'Transform', default=None)
        mmat_bone = array_to_matrix4(elm.props[0]) if elm is not None else None
        elm = elem_find_first(fbx_cdata, b'TransformLink', default=None)
        bmat_glob = array_to_matrix4(elm.props[0]) if elm is not None else Matrix()
        elm = elem_find_first(fbx_cdata, b'TransformAssociateModel', default=None)
        amat_glob = array_to_matrix4(elm.props[0]) if elm is not None else Matrix()

        mmat_glob = bmat_glob * mmat_bone

        # We seek for matrix of bone in armature space...
        bmat_arm = amat_glob.inverted_safe() * bmat_glob

        # Bone correction, works here...
        bmat_loc = (p_ebo.matrix.inverted_safe() * bmat_arm) if p_ebo else bmat_arm
        bmat_loc = bmat_loc * MAT_CONVERT_BONE
        bmat_arm = (p_ebo.matrix * bmat_loc) if p_ebo else bmat_loc
    else:
        # Armature bound to no mesh...
        fbx_cdata, meshes, objects = (None, (), ())
        mmat_bone = None
        amat_glob = bl_obj.matrix_world

        fbx_props = (elem_find_first(fbx_bdata, b'Properties70'),
                     elem_find_first(fbx_tmpl_model, b'Properties70', fbx_elem_nil))
        assert(fbx_props[0] is not None)

        # Bone correction, works here...
        transform_data = blen_read_object_transform_preprocess(fbx_props, fbx_bdata, MAT_CONVERT_BONE)
        bmat_loc = blen_read_object_transform_do(transform_data)
        # Bring back matrix in armature space.
        bmat_arm = (p_ebo.matrix * bmat_loc) if p_ebo else bmat_loc

    # ----
    # Now, create the (edit)bone.
    bone_name = elem_name_ensure_class(fbx_bdata, b'Model')

    ebo = bl_arm.edit_bones.new(name=bone_name)
    bone_name = ebo.name  # Might differ from FBX bone name!
    b_item[1] = bone_name  # since ebo is only valid in Edit mode... :/

    # So that our bone gets its final length, but still Y-aligned in armature space.
    # XXX We now know bsize is not len of bone... but still forbid zero len!
    ebo.tail = Vector((0.0, 1.0, 0.0)) * max(bsize, 1e-3)
    # And rotate/move it to its final "rest pose".
    ebo.matrix = bmat_arm.normalized()

    # Connection to parent.
    if p_ebo is not None:
        ebo.parent = p_ebo
        if similar_values_iter(p_ebo.tail, ebo.head):
            ebo.use_connect = True

    if fbx_cdata is not None:
        # ----
        # Add a new vgroup to the meshes (their objects, actually!).
        # Quite obviously, only one mesh is expected...
        indices = elem_prop_first(elem_find_first(fbx_cdata, b'Indexes', default=None), default=())
        weights = elem_prop_first(elem_find_first(fbx_cdata, b'Weights', default=None), default=())
        add_vgroup_to_objects(indices, weights, bone_name, objects)

    # ----
    # If we get a valid mesh matrix (in bone space), store armature and mesh global matrices, we need to set temporarily
    # both objects to those matrices when actually binding them via the modifier.
    # Note we assume all bones were bound with the same mesh/armature (global) matrix, we do not support otherwise
    # in Blender anyway!
    if mmat_bone is not None:
        for obj in objects:
            if obj in matrices:
                continue
            matrices[obj] = (amat_glob, mmat_glob)

    return ebo


def blen_read_armatures(fbx_tmpl, armatures, fbx_bones_to_fake_object, scene, arm_parents, settings):
    from mathutils import Matrix

    global_matrix = settings.global_matrix
    assert(global_matrix is not None)
    object_tdata_cache = settings.object_tdata_cache

    for a_item, bones in armatures:
        fbx_adata, bl_adata = a_item
        matrices = {}

        # ----
        # Armature data.
        elem_name_utf8 = elem_name_ensure_class(fbx_adata, b'Model')
        bl_arm = bpy.data.armatures.new(name=elem_name_utf8)

        # Need to create the object right now, since we can only add bones in Edit mode... :/
        assert(a_item[1] is None)

        if fbx_adata.props[2] in {b'LimbNode', b'Root'}:
            # rootbone-as-armature case...
            bl_adata = blen_read_object(fbx_tmpl, fbx_adata, bl_arm, settings)
            fbx_bones_to_fake_object[fbx_adata.props[0]] = bl_adata
            # reset transform.
            bl_adata.matrix_basis = Matrix()
        else:
            bl_adata = a_item[1] = blen_read_object(fbx_tmpl, fbx_adata, bl_arm, settings)

        # Instantiate in scene.
        obj_base = scene.objects.link(bl_adata)
        obj_base.select = True

        # Switch to Edit mode.
        scene.objects.active = bl_adata
        is_hidden = bl_adata.hide
        bl_adata.hide = False  # Can't switch to Edit mode hidden objects...
        bpy.ops.object.mode_set(mode='EDIT')

        for b_uuid in bones:
            blen_read_armatures_add_bone(bl_adata, bl_arm, bones, b_uuid, matrices, fbx_tmpl)

        bpy.ops.object.mode_set(mode='OBJECT')
        bl_adata.hide = is_hidden

        # Bind armature to objects.
        arm_mat_back = bl_adata.matrix_basis.copy()
        for ob_me, (amat, mmat) in matrices.items():
            # bring global armature & mesh matrices into *Blender* global space.
            amat = global_matrix * amat
            mmat = global_matrix * mmat

            bl_adata.matrix_basis = amat
            me_mat_back = ob_me.matrix_basis.copy()
            ob_me.matrix_basis = mmat

            mod = ob_me.modifiers.new(elem_name_utf8, 'ARMATURE')
            mod.object = bl_adata

            ob_me.parent = bl_adata
            ob_me.matrix_basis = me_mat_back
            # Store the pair for later space corrections (bring back mesh in parent space).
            arm_parents.add((bl_adata, ob_me))
        bl_adata.matrix_basis = arm_mat_back

        # Set Pose transformations...
        for b_item, _b_size, _p_uuid, _clusters in bones.values():
            fbx_bdata, bl_bname = b_item
            fbx_props = (elem_find_first(fbx_bdata, b'Properties70'),
                         elem_find_first(fbx_tmpl, b'Properties70', fbx_elem_nil))
            assert(fbx_props[0] is not None)

            pbo = b_item[1] = bl_adata.pose.bones[bl_bname]
            transform_data = object_tdata_cache.get(pbo)
            if transform_data is None:
                # Bone correction, gives a mess as result. :(
                transform_data = blen_read_object_transform_preprocess(fbx_props, fbx_bdata, MAT_CONVERT_BONE)
                object_tdata_cache[pbo] = transform_data
            mat = blen_read_object_transform_do(transform_data)
            if pbo.parent:
                # Bring back matrix in armature space.
                mat = pbo.parent.matrix * mat
            pbo.matrix = mat


# ---------
# Animation
def blen_read_animations_curves_iter(fbx_curves, blen_start_offset, fbx_start_offset, fps):
    """
    Get raw FBX AnimCurve list, and yield values for all curves at each singular curves' keyframes,
    together with (blender) timing, in frames.
    blen_start_offset is expected in frames, while fbx_start_offset is expected in FBX ktime.
    """
    # As a first step, assume linear interpolation between key frames, we'll (try to!) handle more
    # of FBX curves later.
    from .fbx_utils import FBX_KTIME
    timefac = fps / FBX_KTIME

    curves = tuple([0,
                    elem_prop_first(elem_find_first(c[2], b'KeyTime')),
                    elem_prop_first(elem_find_first(c[2], b'KeyValueFloat')),
                    c]
                   for c in fbx_curves)

    allkeys = sorted({item for sublist in curves for item in sublist[1]})
    for curr_fbxktime in allkeys:
        curr_values = []
        for item in curves:
            idx, times, values, fbx_curve = item

            if times[idx] < curr_fbxktime:
                if idx >= 0:
                    idx += 1
                    if idx >= len(times):
                        # We have reached our last element for this curve, stay on it from now on...
                        idx = -1
                    item[0] = idx

            if times[idx] >= curr_fbxktime:
                if idx == 0:
                    curr_values.append((values[idx], fbx_curve))
                else:
                    # Interpolate between this key and the previous one.
                    ifac = (curr_fbxktime - times[idx - 1]) / (times[idx] - times[idx - 1])
                    curr_values.append(((values[idx] - values[idx - 1]) * ifac + values[idx - 1], fbx_curve))
        curr_blenkframe = (curr_fbxktime - fbx_start_offset) * timefac + blen_start_offset
        yield (curr_blenkframe, curr_values)


def blen_read_animations_action_item(action, item, cnodes, force_global, fps, settings):
    """
    'Bake' loc/rot/scale into the action, taking into account global_matrix if no parent is present.
    """
    from bpy.types import Object, PoseBone, ShapeKey
    from mathutils import Euler, Matrix
    from itertools import chain

    global_matrix = settings.global_matrix
    object_tdata_cache = settings.object_tdata_cache
    blen_curves = []
    fbx_curves = []
    props = []

    if isinstance(item, ShapeKey):
        props = [(item.path_from_id("value"), 1, "Key")]
    else:  # Object or PoseBone:
        if item not in object_tdata_cache:
            print("ERROR! object '%s' has no transform data, while being animated!" % item.name)
            return

        # We want to create actions for objects, but for bones we 'reuse' armatures' actions!
        grpname = None
        if item.id_data != item:
            grpname = item.name

        # Since we might get other channels animated in the end, due to all FBX transform magic,
        # we need to add curves for whole loc/rot/scale in any case.
        props = [(item.path_from_id("location"), 3, grpname or "Location"),
                 None,
                 (item.path_from_id("scale"), 3, grpname or "Scale")]
        rot_mode = item.rotation_mode
        if rot_mode == 'QUATERNION':
            props[1] = (item.path_from_id("rotation_quaternion"), 4, grpname or "Quaternion Rotation")
        elif rot_mode == 'AXIS_ANGLE':
            props[1] = (item.path_from_id("rotation_axis_angle"), 4, grpname or "Axis Angle Rotation")
        else:  # Euler
            props[1] = (item.path_from_id("rotation_euler"), 3, grpname or "Euler Rotation")

    blen_curves = [action.fcurves.new(prop, channel, grpname)
                   for prop, nbr_channels, grpname in props for channel in range(nbr_channels)]

    for curves, fbxprop in cnodes.values():
        for (fbx_acdata, _blen_data), channel in curves.values():
            fbx_curves.append((fbxprop, channel, fbx_acdata))

    if isinstance(item, ShapeKey):
        # We assume for now blen init point is frame 1.0, while FBX ktime init point is 0.
        for frame, values in blen_read_animations_curves_iter(fbx_curves, 1.0, 0, fps):
            value = 0.0
            for v, (fbxprop, channel, _fbx_acdata) in values:
                assert(fbxprop == b'DeformPercent')
                assert(channel == 0)
                value = v / 100.0

            for fc, v in zip(blen_curves, (value,)):
                fc.keyframe_points.insert(frame, v, {'NEEDED', 'FAST'}).interpolation = 'LINEAR'

    else:  # Object or PoseBone:
        transform_data = object_tdata_cache[item]
        rot_prev = item.rotation_euler.copy()

        # Pre-compute inverted local rest matrix of the bone, if relevant.
        if isinstance(item, PoseBone):
            # First, get local (i.e. parentspace) rest pose matrix
            restmat = item.bone.matrix_local
            if item.parent:
                restmat = item.parent.bone.matrix_local.inverted_safe() * restmat
            restmat_inv = restmat.inverted_safe()

        # We assume for now blen init point is frame 1.0, while FBX ktime init point is 0.
        for frame, values in blen_read_animations_curves_iter(fbx_curves, 1.0, 0, fps):
            for v, (fbxprop, channel, _fbx_acdata) in values:
                if fbxprop == b'Lcl Translation':
                    transform_data.loc[channel] = v
                elif fbxprop == b'Lcl Rotation':
                    transform_data.rot[channel] = v
                elif fbxprop == b'Lcl Scaling':
                    transform_data.sca[channel] = v
            mat = blen_read_object_transform_do(transform_data)
            # Don't forget global matrix - but never for bones!
            if isinstance(item, Object):
                if (not item.parent or force_global) and global_matrix is not None:
                    mat = global_matrix * mat
            else:  # PoseBone, Urg!
                # And now, remove that rest pose matrix from current mat (also in parent space).
                mat = restmat_inv * mat

            # Now we have a virtual matrix of transform from AnimCurves, we can insert keyframes!
            loc, rot, sca = mat.decompose()
            if rot_mode == 'QUATERNION':
                pass  # nothing to do!
            elif rot_mode == 'AXIS_ANGLE':
                vec, ang = rot.to_axis_angle()
                rot = ang, vec.x, vec.y, vec.z
            else:  # Euler
                rot = rot.to_euler(rot_mode, rot_prev)
                rot_prev = rot
            for fc, value in zip(blen_curves, chain(loc, rot, sca)):
                fc.keyframe_points.insert(frame, value, {'NEEDED', 'FAST'}).interpolation = 'LINEAR'

    # Since we inserted our keyframes in 'FAST' mode, we have to update the fcurves now.
    for fc in blen_curves:
        fc.update()


def blen_read_animations(fbx_tmpl_astack, fbx_tmpl_alayer, stacks, scene, force_global_objects, settings):
    """
    Recreate an action per stack/layer/object combinations.
    Note actions are not linked to objects, this is up to the user!
    """
    actions = {}
    for as_uuid, ((fbx_asdata, _blen_data), alayers) in stacks.items():
        stack_name = elem_name_ensure_class(fbx_asdata, b'AnimStack')
        for al_uuid, ((fbx_aldata, _blen_data), items) in alayers.items():
            layer_name = elem_name_ensure_class(fbx_aldata, b'AnimLayer')
            for item, cnodes in items.items():
                id_data = item.id_data
                key = (as_uuid, al_uuid, id_data)
                action = actions.get(key)
                if action is None:
                    action_name = "|".join((id_data.name, stack_name, layer_name))
                    actions[key] = action = bpy.data.actions.new(action_name)
                    action.use_fake_user = True
                blen_read_animations_action_item(action, item, cnodes,
                                                 item in force_global_objects, scene.render.fps, settings)


# ----
# Mesh

def blen_read_geom_layerinfo(fbx_layer):
    return (
        elem_find_first_string(fbx_layer, b'Name'),
        elem_find_first_bytes(fbx_layer, b'MappingInformationType'),
        elem_find_first_bytes(fbx_layer, b'ReferenceInformationType'),
        )


def blen_read_geom_array_mapped_vert(
        mesh, blen_data, blend_attr,
        fbx_layer_data, fbx_layer_index,
        fbx_layer_mapping, fbx_layer_ref,
        stride, item_size, descr,
        ):
    # TODO, generic mapping apply function
    if fbx_layer_mapping == b'ByVertice':
        if fbx_layer_ref == b'Direct':
            assert(fbx_layer_index is None)
            # TODO, more generic support for mapping types
            for i, blen_data_item in enumerate(blen_data):
                setattr(blen_data_item, blend_attr,
                        fbx_layer_data[(i * stride): (i * stride) + item_size])
            return True
        else:
            print("warning layer %r ref type unsupported: %r" % (descr, fbx_layer_ref))
    else:
        print("warning layer %r mapping type unsupported: %r" % (descr, fbx_layer_mapping))

    return False


def blen_read_geom_array_mapped_edge(
        mesh, blen_data, blend_attr,
        fbx_layer_data, fbx_layer_index,
        fbx_layer_mapping, fbx_layer_ref,
        stride, item_size, descr,
        xform=None,
        ):
    if fbx_layer_mapping == b'ByEdge':
        if fbx_layer_ref == b'Direct':
            if stride == 1:
                if xform is None:
                    for i, blen_data_item in enumerate(blen_data):
                        setattr(blen_data_item, blend_attr,
                                fbx_layer_data[i])
                else:
                    for i, blen_data_item in enumerate(blen_data):
                        setattr(blen_data_item, blend_attr,
                                xform(fbx_layer_data[i]))
            else:
                if xform is None:
                    for i, blen_data_item in enumerate(blen_data):
                        setattr(blen_data_item, blend_attr,
                                fbx_layer_data[(i * stride): (i * stride) + item_size])
                else:
                    for i, blen_data_item in enumerate(blen_data):
                        setattr(blen_data_item, blend_attr,
                                xform(fbx_layer_data[(i * stride): (i * stride) + item_size]))
            return True
        else:
            print("warning layer %r ref type unsupported: %r" % (descr, fbx_layer_ref))
    else:
        print("warning layer %r mapping type unsupported: %r" % (descr, fbx_layer_mapping))

    return False


def blen_read_geom_array_mapped_polygon(
        mesh, blen_data, blend_attr,
        fbx_layer_data, fbx_layer_index,
        fbx_layer_mapping, fbx_layer_ref,
        stride, item_size, descr,
        xform=None,
        ):
    if fbx_layer_mapping == b'ByPolygon':
        if fbx_layer_ref == b'IndexToDirect':
            if stride == 1:
                for i, blen_data_item in enumerate(blen_data):
                    setattr(blen_data_item, blend_attr,
                            fbx_layer_data[i])
            else:
                for i, blen_data_item in enumerate(blen_data):
                    setattr(blen_data_item, blend_attr,
                            fbx_layer_data[(i * stride): (i * stride) + item_size])
            return True
        elif fbx_layer_ref == b'Direct':
            # looks like direct may have different meanings!
            assert(stride == 1)
            if xform is None:
                for i in range(len(fbx_layer_data)):
                    setattr(blen_data[i], blend_attr, fbx_layer_data[i])
            else:
                for i in range(len(fbx_layer_data)):
                    setattr(blen_data[i], blend_attr, xform(fbx_layer_data[i]))
            return True
        else:
            print("warning layer %r ref type unsupported: %r" % (descr, fbx_layer_ref))
    else:
        print("warning layer %r mapping type unsupported: %r" % (descr, fbx_layer_mapping))

    return False


def blen_read_geom_array_mapped_polyloop(
        mesh, blen_data, blend_attr,
        fbx_layer_data, fbx_layer_index,
        fbx_layer_mapping, fbx_layer_ref,
        stride, item_size, descr,
        ):
    if fbx_layer_mapping == b'ByPolygonVertex':
        if fbx_layer_ref == b'IndexToDirect':
            assert(fbx_layer_index is not None)
            for i, j in enumerate(fbx_layer_index):
                if j != -1:
                    setattr(blen_data[i], blend_attr,
                            fbx_layer_data[(j * stride): (j * stride) + item_size])
            return True
        else:
            print("warning layer %r ref type unsupported: %r" % (descr, fbx_layer_ref))
    elif fbx_layer_mapping == b'ByVertice':
        if fbx_layer_ref == b'Direct':
            assert(fbx_layer_index is None)
            loops = mesh.loops
            polygons = mesh.polygons
            for p in polygons:
                for i in p.loop_indices:
                    j = loops[i].vertex_index
                    setattr(blen_data[i], blend_attr,
                            fbx_layer_data[(j * stride): (j * stride) + item_size])
        else:
            print("warning layer %r ref type unsupported: %r" % (descr, fbx_layer_ref))
    else:
        print("warning layer %r mapping type unsupported: %r" % (descr, fbx_layer_mapping))

    return False


def blen_read_geom_layer_material(fbx_obj, mesh):
    fbx_layer = elem_find_first(fbx_obj, b'LayerElementMaterial')

    if fbx_layer is None:
        return

    (fbx_layer_name,
     fbx_layer_mapping,
     fbx_layer_ref,
     ) = blen_read_geom_layerinfo(fbx_layer)

    if fbx_layer_mapping == b'AllSame':
        # only to quiet warning
        return

    layer_id = b'Materials'
    fbx_layer_data = elem_prop_first(elem_find_first(fbx_layer, layer_id))

    blen_data = mesh.polygons
    blen_read_geom_array_mapped_polygon(
        mesh, blen_data, "material_index",
        fbx_layer_data, None,
        fbx_layer_mapping, fbx_layer_ref,
        1, 1, layer_id,
        )


def blen_read_geom_layer_uv(fbx_obj, mesh):
    for layer_id in (b'LayerElementUV',):
        for fbx_layer in elem_find_iter(fbx_obj, layer_id):
            # all should be valid
            (fbx_layer_name,
             fbx_layer_mapping,
             fbx_layer_ref,
             ) = blen_read_geom_layerinfo(fbx_layer)

            fbx_layer_data = elem_prop_first(elem_find_first(fbx_layer, b'UV'))
            fbx_layer_index = elem_prop_first(elem_find_first(fbx_layer, b'UVIndex'))

            uv_tex = mesh.uv_textures.new(name=fbx_layer_name)