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Bastien Montagne authored
What to expect: * Static export of empties, meshes, cameras and lamps, as well as materials and (image!) textures should work OK. There are a few advanced topics still TODO regarding meshes and mat/tex, though. * Custom properties from objects/meshes/lamps/cameras/armatures/bones/materials/textures are exported too (only simple ones, ints/floats/strings). * Armature export: this needs testing by people having *native* FBX aplications, linking between bones and meshes seems to work, but I have doubts about bones orientations. * Animation: still a complete TODO. Note that old FBX ASCII 6.1 exporter is still available (top dropdown in exporter's UI). Many thanks to Campbell, which did the ground work of decyphering FBX binary format and wrote basic code to read/write it.
Bastien Montagne authoredWhat to expect: * Static export of empties, meshes, cameras and lamps, as well as materials and (image!) textures should work OK. There are a few advanced topics still TODO regarding meshes and mat/tex, though. * Custom properties from objects/meshes/lamps/cameras/armatures/bones/materials/textures are exported too (only simple ones, ints/floats/strings). * Armature export: this needs testing by people having *native* FBX aplications, linking between bones and meshes seems to work, but I have doubts about bones orientations. * Animation: still a complete TODO. Note that old FBX ASCII 6.1 exporter is still available (top dropdown in exporter's UI). Many thanks to Campbell, which did the ground work of decyphering FBX binary format and wrote basic code to read/write it.
encode_bin.py 9.59 KiB
# ##### 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) 2013 Campbell Barton
try:
from . import data_types
except:
import data_types
from struct import pack
import array
import zlib
_BLOCK_SENTINEL_LENGTH = 13
_BLOCK_SENTINEL_DATA = (b'\0' * _BLOCK_SENTINEL_LENGTH)
_IS_BIG_ENDIAN = (__import__("sys").byteorder != 'little')
_HEAD_MAGIC = b'Kaydara FBX Binary\x20\x20\x00\x1a\x00'
# fbx has very strict CRC rules, all based on file timestamp
# until we figure these out, write files at a fixed time. (workaround!)
# Assumes: CreationTime
_TIME_ID = b'1970-01-01 10:00:00:000'
_FILE_ID = b'\x28\xb3\x2a\xeb\xb6\x24\xcc\xc2\xbf\xc8\xb0\x2a\xa9\x2b\xfc\xf1'
_FOOT_ID = b'\xfa\xbc\xab\x09\xd0\xc8\xd4\x66\xb1\x76\xfb\x83\x1c\xf7\x26\x7e'
class FBXElem:
__slots__ = (
"id",
"props",
"props_type",
"elems",
"_props_length", # combine length of props
"_end_offset", # byte offset from the start of the file.
)
def __init__(self, id):
assert(len(id) < 256) # length must fit in a uint8
self.id = id
self.props = []
self.props_type = bytearray()
self.elems = []
self._end_offset = -1
self._props_length = -1
def add_bool(self, data):
assert(isinstance(data, bool))
data = pack('?', data)
self.props_type.append(data_types.BOOL)
self.props.append(data)
def add_int16(self, data):
assert(isinstance(data, int))
data = pack('<h', data)
self.props_type.append(data_types.INT16)
self.props.append(data)
def add_int32(self, data):
assert(isinstance(data, int))
data = pack('<i', data)
self.props_type.append(data_types.INT32)
self.props.append(data)
def add_int64(self, data):
assert(isinstance(data, int))
data = pack('<q', data)
self.props_type.append(data_types.INT64)
self.props.append(data)
def add_float32(self, data):
assert(isinstance(data, float))
data = pack('<f', data)
self.props_type.append(data_types.FLOAT32)
self.props.append(data)
def add_float64(self, data):
assert(isinstance(data, float))
data = pack('<d', data)
self.props_type.append(data_types.FLOAT64)
self.props.append(data)
def add_bytes(self, data):
assert(isinstance(data, bytes))
data = pack('<I', len(data)) + data
self.props_type.append(data_types.BYTES)
self.props.append(data)
def add_string(self, data):
assert(isinstance(data, bytes))
data = pack('<I', len(data)) + data
self.props_type.append(data_types.STRING)
self.props.append(data)
def add_string_unicode(self, data):
assert(isinstance(data, str))
data = data.encode('utf8')
data = pack('<I', len(data)) + data
self.props_type.append(data_types.STRING)
self.props.append(data)
def _add_array_helper(self, data, array_type, prop_type):
assert(isinstance(data, array.array))
assert(data.typecode == array_type)
length = len(data)
if _IS_BIG_ENDIAN:
data = data[:]
data.byteswap()
data = data.tobytes()
# mimic behavior of fbxconverter (also common sense)
# we could make this configurable.
encoding = 0 if len(data) <= 128 else 1
if encoding == 0:
pass
elif encoding == 1:
data = zlib.compress(data, 1)
comp_len = len(data)
data = pack('<3I', length, encoding, comp_len) + data
self.props_type.append(prop_type)
self.props.append(data)
def add_int32_array(self, data):
if not isinstance(data, array.array):
data = array.array(data_types.ARRAY_INT32, data)
self._add_array_helper(data, data_types.ARRAY_INT32, data_types.INT32_ARRAY)
def add_int64_array(self, data):
if not isinstance(data, array.array):
data = array.array(data_types.ARRAY_INT64, data)
self._add_array_helper(data, data_types.ARRAY_INT64, data_types.INT64_ARRAY)
def add_float32_array(self, data):
if not isinstance(data, array.array):
data = array.array(data_types.ARRAY_FLOAT32, data)
self._add_array_helper(data, data_types.ARRAY_FLOAT32, data_types.FLOAT32_ARRAY)
def add_float64_array(self, data):
if not isinstance(data, array.array):
data = array.array(data_types.ARRAY_FLOAT64, data)
self._add_array_helper(data, data_types.ARRAY_FLOAT64, data_types.FLOAT64_ARRAY)
def add_bool_array(self, data):
if not isinstance(data, array.array):
data = array.array(data_types.ARRAY_BOOL, data)
self._add_array_helper(data, data_types.ARRAY_BOOL, data_types.BOOL_ARRAY)
def add_byte_array(self, data):
if not isinstance(data, array.array):
data = array.array(data_types.ARRAY_BYTE, data)
self._add_array_helper(data, data_types.ARRAY_BYTE, data_types.BYTE_ARRAY)
# -------------------------
# internal helper functions
def _calc_offsets(self, offset, is_last):
"""
Call before writing, calculates fixed offsets.
"""
assert(self._end_offset == -1)
assert(self._props_length == -1)
# print("Offset", offset)
offset += 12 # 3 uints
offset += 1 + len(self.id) # len + idname
props_length = 0
for data in self.props:
# 1 byte for the prop type
props_length += 1 + len(data)
self._props_length = props_length
offset += props_length
offset = self._calc_offsets_children(offset, is_last)
self._end_offset = offset
return offset
def _calc_offsets_children(self, offset, is_last):
if self.elems:
elem_last = self.elems[-1]
for elem in self.elems:
offset = elem._calc_offsets(offset, (elem is elem_last))
offset += _BLOCK_SENTINEL_LENGTH
elif not self.props:
if not is_last:
offset += _BLOCK_SENTINEL_LENGTH
return offset
def _write(self, write, tell, is_last):
assert(self._end_offset != -1)
assert(self._props_length != -1)
# print(self.id, self._end_offset, len(self.props), self._props_length)
write(pack('<3I', self._end_offset, len(self.props), self._props_length))
write(bytes((len(self.id),)))
write(self.id)
for i, data in enumerate(self.props):
write(bytes((self.props_type[i],)))
write(data)
self._write_children(write, tell, is_last)
if tell() != self._end_offset:
raise IOError("scope length not reached, "
"something is wrong (%d)" % (end_offset - tell()))
def _write_children(self, write, tell, is_last):
if self.elems:
elem_last = self.elems[-1]
for elem in self.elems:
assert(elem.id != b'')
elem._write(write, tell, (elem is elem_last))
write(_BLOCK_SENTINEL_DATA)
elif not self.props:
if not is_last:
write(_BLOCK_SENTINEL_DATA)
def _write_timedate_hack(elem_root):
# perform 2 changes
# - set the FileID
# - set the CreationTime
ok = 0
for elem in elem_root.elems:
if elem.id == b'FileId':
assert(elem.props_type[0] == b'R'[0])
assert(len(elem.props_type) == 1)
elem.props.clear()
elem.props_type.clear()
elem.add_bytes(_FILE_ID)
ok += 1
elif elem.id == b'CreationTime':
assert(elem.props_type[0] == b'S'[0])
assert(len(elem.props_type) == 1)
elem.props.clear()
elem.props_type.clear()
elem.add_string(_TIME_ID)
ok += 1
if ok == 2:
break
if ok != 2:
print("Missing fields!")
def write(fn, elem_root, version):
assert(elem_root.id == b'')
with open(fn, 'wb') as f:
write = f.write
tell = f.tell
write(_HEAD_MAGIC)
write(pack('<I', version))
# hack since we don't decode time.
# ideally we would _not_ modify this data.
_write_timedate_hack(elem_root)
elem_root._calc_offsets_children(tell(), False)
elem_root._write_children(write, tell, False)
write(_FOOT_ID)
write(b'\x00' * 4)
# padding for alignment (values between 1 & 16 observed)
# if already aligned to 16, add a full 16 bytes padding.
ofs = tell()
pad = ((ofs + 15) & ~15) - ofs
if pad == 0:
pad = 16
write(b'\0' * pad)
write(pack('<I', version))
# unknown magic (always the same)
write(b'\0' * 120)
write(b'\xf8\x5a\x8c\x6a\xde\xf5\xd9\x7e\xec\xe9\x0c\xe3\x75\x8f\x29\x0b')