Blender crashes on FBX export instantly. #40405

New Issue

Bastien Montagne · 2014-05-28T11:42:51+02:00

Dancuka commented

2014-05-28 11:42:51 +02:00

(Migrated from localhost:3001)

System Information
Windows 7 , GTX650TI

Blender Version
Broken: 2.70a official Hash: 19e627c
Worked: 2.68.0 r58537

Blender crashes and closes instantly if exporting object with faulty and flipped normals. At least that is what I think is the cause. I managed to test this and also pinpointed how to fix it. The cause seems to be some flipped normals on faces. If some of the normals on faces on the same mesh are flipped or it has 2 faces on it self(double sided) the export crashes. I think that the mesh in the attached scene was created the way that the faces were duplicated on the same location and flipped (to create 2sided effect maybe) but then the automerge vertexes was on and the mesh got messed up when points got welded. So some of the face-normals are up and some are down.

Exact steps for others to reproduce the error
1, Select object in scene, notice that some of the normals are messed up. Dont fix them yet.
2, Try exporting fbx with the following setting on the FBXexporter: Everthing disabled, except "apply modifiers". Only export "mesh" tab selected also. (not sure if these settings matter but these were my settings) Sometimes it crashes with OBJ exporting also but that seems more random. Might have to do something with the export settings.
3, When pressing export button Blender closes instantly(crash). A file might be outputted but its corrupted.

HOW TO FIX:

If you select all the mesh in editmode and press "Recalculate Normals" the face-normals are on the same side. Try exporting it works. BUT: I tried exporting in 2.68 with the messed up normals and it worked fine there. The normals are just flipped and messed up but the exporting works there. This crashing seems to happen only in the recent builds.export_crashtest.blend

**System Information** Windows 7 , GTX650TI **Blender Version** Broken: 2.70a official Hash: 19e627c Worked: 2.68.0 r58537 Blender crashes and closes instantly if exporting object with faulty and flipped normals. At least that is what I think is the cause. I managed to test this and also pinpointed how to fix it. The cause seems to be some flipped normals on faces. If some of the normals on faces on the same mesh are flipped or it has 2 faces on it self(double sided) the export crashes. I think that the mesh in the attached scene was created the way that the faces were duplicated on the same location and flipped (to create 2sided effect maybe) but then the automerge vertexes was on and the mesh got messed up when points got welded. So some of the face-normals are up and some are down. **Exact steps for others to reproduce the error** 1, Select object in scene, **notice that some of the normals are messed up.** Dont fix them yet. 2, Try exporting fbx with the following setting on the FBXexporter: Everthing disabled, except "apply modifiers". Only export "mesh" tab selected also. (not sure if these settings matter but these were my settings) Sometimes it crashes with OBJ exporting also but that seems more random. Might have to do something with the export settings. 3, When pressing export button Blender closes instantly(crash). A file might be outputted but its corrupted. HOW TO FIX: If you select all the mesh in editmode and press "Recalculate Normals" the face-normals are on the same side. Try exporting it works. BUT: I tried exporting in 2.68 with the messed up normals and it worked fine there. The normals are just flipped and messed up but the exporting works there. This crashing seems to happen only in the recent builds.[export_crashtest.blend](https://archive.blender.org/developer/F91692/export_crashtest.blend)

Dancuka commented

2014-05-28 11:42:51 +02:00

(Migrated from localhost:3001)

Changed status to: 'Open'

Dancuka commented

2014-05-28 11:42:51 +02:00

(Migrated from localhost:3001)

Added subscriber: @Dancuka

Dancuka commented

2014-05-28 11:48:29 +02:00

(Migrated from localhost:3001)

This bug can cause some lost data and work if user has not saved in a while and the backups are not up to date. The crash is instant without warning and if file was not saved work is lost :(

Bastien Montagne was assigned by Sergey Sharybin

2014-05-28 11:50:39 +02:00

Sergey Sharybin commented

2014-05-28 11:50:39 +02:00

Added subscribers: @mont29, @Sergey