FBX export error because of invalid NaN UV values. #102783

New Issue

Paul Kotelevets · 2022-11-26T02:05:33+01:00

Paul Kotelevets commented

2022-11-26 02:05:33 +01:00

System Information
Operating system: Linux-4.15.0-51-generic-x86_64-with-glibc2.27 64 Bits
Graphics card: GeForce GTX 850M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 390.143

Blender Version
Broken: version: 3.3.1, branch: master, commit date: 2022-10-04 18:35, hash: b292cfe5a9
Worked: never

Short description of error
Export of an element from attached file in FBX format cause error until UV is not removed.
Tested on 3.2, 3.3.1, 2.79

3.2 fbx error.blend

Python: Traceback (most recent call last):
  File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\__init__.py", line 655, in execute
    return export_fbx_bin.save(self, context, **keywords)
  File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 3243, in save
    ret = save_single(operator, context.scene, depsgraph, filepath, **kwargs_mod)
  File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 3134, in save_single
    fbx_objects_elements(root, scene_data)
  File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 2932, in fbx_objects_elements
    fbx_data_mesh_elements(objects, me_obj, scene_data, done_meshes)
  File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 1179, in fbx_data_mesh_elements
    elem_data_single_int32_array(lay_uv, b"UVIndex", (uv2idx[uv_id] for uv_id in _uvtuples_gen(t_luv, t_lvidx)))
  File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\fbx_utils.py", line 494, in elem_data_single_int32_array
    return _elem_data_single(elem, name, value, "add_int32_array")
  File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\fbx_utils.py", line 441, in _elem_data_single
    getattr(sub_elem, func_name)(value)
  File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\encode_bin.py", line 143, in add_int32_array
    data = array.array(data_types.ARRAY_INT32, data)
  File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 1179, in <genexpr>
    elem_data_single_int32_array(lay_uv, b"UVIndex", (uv2idx[uv_id] for uv_id in _uvtuples_gen(t_luv, t_lvidx)))
KeyError: ((nan, nan), 34)

**System Information** Operating system: Linux-4.15.0-51-generic-x86_64-with-glibc2.27 64 Bits Graphics card: GeForce GTX 850M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 390.143 **Blender Version** Broken: version: 3.3.1, branch: master, commit date: 2022-10-04 18:35, hash: `b292cfe5a9` Worked: never **Short description of error** Export of an element from attached file in FBX format cause error until UV is not removed. Tested on 3.2, 3.3.1, 2.79 [3.2 fbx error.blend](https://archive.blender.org/developer/F13969916/3.2_fbx_error.blend) ```lines=10 Python: Traceback (most recent call last): File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\__init__.py", line 655, in execute return export_fbx_bin.save(self, context, **keywords) File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 3243, in save ret = save_single(operator, context.scene, depsgraph, filepath, **kwargs_mod) File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 3134, in save_single fbx_objects_elements(root, scene_data) File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 2932, in fbx_objects_elements fbx_data_mesh_elements(objects, me_obj, scene_data, done_meshes) File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 1179, in fbx_data_mesh_elements elem_data_single_int32_array(lay_uv, b"UVIndex", (uv2idx[uv_id] for uv_id in _uvtuples_gen(t_luv, t_lvidx))) File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\fbx_utils.py", line 494, in elem_data_single_int32_array return _elem_data_single(elem, name, value, "add_int32_array") File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\fbx_utils.py", line 441, in _elem_data_single getattr(sub_elem, func_name)(value) File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\encode_bin.py", line 143, in add_int32_array data = array.array(data_types.ARRAY_INT32, data) File "C:\Users\prati\OneDrive\Desktop\BlenderOSP\2022_lite_ninja\bin\3.5\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 1179, in <genexpr> elem_data_single_int32_array(lay_uv, b"UVIndex", (uv2idx[uv_id] for uv_id in _uvtuples_gen(t_luv, t_lvidx))) KeyError: ((nan, nan), 34) ```

Paul Kotelevets commented

2022-11-26 02:05:33 +01:00

Added subscriber: @1D_Inc

blender-admin commented

2022-11-26 02:05:33 +01:00

blender/blender-addons#103583 was marked as duplicate of this issue

blender-admin commented

2022-11-26 02:05:33 +01:00

#103476 was marked as duplicate of this issue

Paul Kotelevets commented

2022-11-26 02:06:48 +01:00

Screenshot of an error

Screenshot of an error ![image.png](https://archive.blender.org/developer/F13969922/image.png)

Scurest commented

2022-11-26 02:14:43 +01:00

Added subscriber: @scurest

Scurest commented

2022-11-26 02:14:43 +01:00

Cf #79775

Pratik Borhade commented

2022-11-26 12:54:32 +01:00

Added subscribers: @lichtwerk, @PratikPB2123

Pratik Borhade commented

2022-11-26 12:54:32 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Pratik Borhade commented

2022-11-26 12:54:32 +01:00

@lichtwerk , looks like issue #79775 is not resolved yet

Pratik Borhade commented

2022-12-27 05:23:17 +01:00

Added subscriber: @96artem1

Scurest commented

2022-12-28 01:45:28 +01:00

Removed subscriber: @scurest

Pratik Borhade commented

2023-01-02 03:38:10 +01:00

Added subscribers: @JJC, @mod_moder

Mysteryem commented

2023-01-17 18:40:05 +01:00

Added subscriber: @Mysteryem-2

Bastien Montagne commented

2023-01-23 15:34:12 +01:00

Added subscriber: @mont29

Bastien Montagne commented

2023-01-23 15:34:12 +01:00

Changed status from 'Confirmed' to: 'Needs User Info'

Bastien Montagne commented

2023-01-23 15:34:12 +01:00

For the records, this is NOT an issue in the FBX code, but in Blender, as stated in #79775, there should be no NaN values in mesh data, this is no valid data.

Would also be good to have info about how that .blend file was generated, we cannot handle data corruption cases just by getting the end result usually, we need steps to reproduce such data corruption.

For the records, this is NOT an issue in the FBX code, but in Blender, as stated in #79775, there should be no NaN values in mesh data, this is no valid data. Would also be good to have info about how that .blend file was generated, we cannot handle data corruption cases just by getting the end result usually, we need steps to reproduce such data corruption.

Bastien Montagne changed title from ~~FBX export error because of UV~~ to FBX export error because of invalid NaN UV values.

2023-01-23 15:35:10 +01:00

Paul Kotelevets commented

2023-01-24 08:29:49 +01:00

Such cases are extremely rare, it is hard to find the exact actions sequence. So, this is because of invalid mesh data.
Is it possible to detect such data with a special function?

Such cases are extremely rare, it is hard to find the exact actions sequence. So, this is because of invalid mesh data. Is it possible to detect such data with a special function?

mijunglee commented

2023-01-24 11:26:45 +01:00

Thank you for your reply~ I couldn't solve the problem, so I recreated it and worked on it. ~^^;;

Bastien Montagne commented

2023-01-24 11:53:03 +01:00

@1D_Inc Mesh.validate() should catch and fix these now, at least in master (not sure when UVMaps where moved to the new generic attribute system, old UVMaps did not check for invalid number values, new float attributes do).

@1D_Inc [Mesh.validate()](https://docs.blender.org/api/master/bpy.types.Mesh.html#bpy.types.Mesh.validate) should catch and fix these now, at least in master (not sure when UVMaps where moved to the new generic attribute system, old UVMaps did not check for invalid number values, new float attributes do).

mijunglee commented

2023-01-24 14:19:58 +01:00

Sorry, but what is 'invalid NaN UV values'~?

Bastien Montagne commented

2023-01-24 15:27:32 +01:00

'NaN' is a short for 'Not a Number', a computer way to represent invalid/'impossible' numbers, like e.g. the result of a division by zero. Such values should never exist in Blender mesh data.

'NaN' is a short for '[Not a Number](https://en.wikipedia.org/wiki/NaN)', a computer way to represent invalid/'impossible' numbers, like e.g. the result of a division by zero. Such values should never exist in Blender mesh data.

mijunglee commented

2023-01-25 03:46:26 +01:00

When I tried to merge 10 pieces and export them, I got an error. Is it possible that this problem may occur in the process of merging mash~? Or can it be caused by not doing UV unwrap~?

Philipp Oeser removed the

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FBX export error because of invalid NaN UV values. #102783