struct.error: unpack requires a buffer of 4 bytes

Blender 2.80 Beta [ Date: 2019-03-03 Hash: ae977d13f8e9 ] SourceIO v3.3.6 https://github.com/REDxEYE/SourceIO/releases/download/3.3.6/SourceIO.zip 4c2752f

Attempting to import a MDL v48: https://sta.sh/09oqflbli8o Please let me know if you’re unable to download the model.

MDL file type ID: IDST
MDL file version: 48
MDL stored file name: "characters/postal_babe/postal_babe.mdl"
MDL stored file size: 250,960 bytes
MDL actual file size: 250,960 bytes
MDL checksum: 9925ED6E

When the model failed to import, the following error message appeared:

 Traceback (most recent call last):
  File "C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.80\scripts\addons\SourceIO\__init__.py", line 58, in execute
    importer.load()
  File "C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.80\scripts\addons\SourceIO\mdl2model.py", line 70, in load
    self.model.read()
  File "C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.80\scripts\addons\SourceIO\source_model.py", line 46, in read
    self.mdl.read()
  File "C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.80\scripts\addons\SourceIO\mdl_readers\mdl_v48.py", line 22, in read
    self.read_bone_flex_drivers()
  File "C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.80\scripts\addons\SourceIO\mdl_readers\mdl_v48.py", line 180, in read_bone_flex_drivers
    mouth.read(self.reader)
  File "C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.80\scripts\addons\SourceIO\data_structures\mdl_data.py", line 1458, in read
    self.bone = reader.read_int32()
  File "C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.80\scripts\addons\SourceIO\byte_io_mdl.py", line 175, in read_int32
    return self.read('i')
  File "C:\Users\User\AppData\Roaming\Blender Foundation\Blender\2.80\scripts\addons\SourceIO\byte_io_mdl.py", line 159, in read
    return struct.unpack(t, self._read(size))[0]
struct.error: unpack requires a buffer of 4 bytes

location: <unknown location>:-1

[REDxEYE]

This is the problem i know about, LODs my addon does not resolve them correctly

[0Curtain0]

This is the problem i know about, LODs my addon does not resolve them correctly

@REDxEYE I forgot to ask, do you want to open a separate issue for the LOD problem? This way it would be easier to track LOD and struct.error problem separately.

I did a new test with a different SFM model: https://sfmlab.com/item/3709/ Operating System: Pop!_OS 64bit (Based on Ubuntu) Blender 2.81a (non-Steam version / tar.bz2) SourceIO: 3.5.8

On fresh Blender startup (Blender wasn’t running before), I tried to import mechari_female_beta_bigger4_edit.mdl, and it imports successfully.

I CTRL+Z to undo the import, and then import the postal_babe.mdl (from before). The postal_babe.mdl imports into Blender but has the LOD problem, as mentioned before, ok.

I CTRL+Z again to undo the postal_babe.mdl import, and then import mechari_female_beta_bigger4_edit.mdl again, but this time I get the following error:

Traceback (most recent call last):
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 55, in read
    SourceVtxBodyPart().read(reader))
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 135, in read
    self.vtx_models.append(SourceVtxModel().read(reader))
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 156, in read
    SourceVtxModelLod().read(reader, self))
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 181, in read
    self.vtx_meshes.append(SourceVtxMesh().read(reader))
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 207, in read
    SourceVtxStripGroup().read(reader))
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 266, in read
    SourceVtxStrip().read(reader, self)
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 330, in read
    self.bone_count = reader.read_uint16()
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/byte_io_mdl.py", line 177, in read_uint16
    return self.read('H')
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/byte_io_mdl.py", line 158, in read
    return struct.unpack(t, self._read(size))[0]
struct.error: unpack requires a buffer of 2 bytes

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/__init__.py", line 86, in execute
    importer.load(dont_build_mesh=False)
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/mdl/mdl2model.py", line 80, in load
    self.model.read()
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/mdl/source_model.py", line 63, in read
    self.vtx.read()
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/mdl/vtx_readers/vtx_v7.py", line 17, in read
    self.vtx.read(self.reader)
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 63, in read
    SourceVtxBodyPart().read(reader))
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 135, in read
    self.vtx_models.append(SourceVtxModel().read(reader))
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 156, in read
    SourceVtxModelLod().read(reader, self))
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 181, in read
    self.vtx_meshes.append(SourceVtxMesh().read(reader))
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 207, in read
    SourceVtxStripGroup().read(reader))
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 266, in read
    SourceVtxStrip().read(reader, self)
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/data_structures/vtx_data.py", line 330, in read
    self.bone_count = reader.read_uint16()
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/byte_io_mdl.py", line 177, in read_uint16
    return self.read('H')
  File "/home/user/.config/blender/2.81/scripts/addons/SourceIO/byte_io_mdl.py", line 158, in read
    return struct.unpack(t, self._read(size))[0]
struct.error: unpack requires a buffer of 2 bytes

location: <unknown location>:-1

Importing the mechari_butt.mdl appears to have no issues.

I tried File - New - General, then tried to import the mechari_female_beta_bigger4_edit.mdl again, but similar error.

It appears that the mechari_female_beta_bigger4_edit.mdl will import correctly again if I exit Blender and start it up again. However, if I import that postal_babe.mdl into Blender first, and then try to import the mechari_female_beta_bigger4_edit.mdl, the import will produce the error.

I’m on 64bit Linux, so I have no idea if this can be understood by someone who doesn’t use Linux, and I’m not 100% sure if this is a Linux only problem.

Anyway, I did mention before that there was another Blender add-on (RipImport) I was using that has a similar problem with struct.error, and a user named @luchador3d is trying to help debug it:

• https://github.com/xpawelsky/RipImport/issues/1#issuecomment-552216569

I recently started working on a SFM to Blender guide: Blender - Play with SFM Models but because of the current bugs that I’m experiencing on Linux, I won’t be able to do some new demos for the guide.