Fix duplicate shape key import when the FBX connections are duplicated #104954

Thomas Barlow · 2023-10-15T05:02:20+02:00

Thomas Barlow commented

2023-10-15 05:02:20 +02:00

Rarely, FBX files with duplicate ShapeKey-related connections are
encountered. The FBX IO addon would add a ShapeKey for each duplicate,
however external software appears to ignore the duplicates, or
overwrite the existing duplicates such that the same effect as ignoring
new duplicates is achieved.

This patch modifies the FBX importer to skip all duplicate ShapeKey-
related connections when finding the ShapeKeys to add to each Mesh.

While it is unclear if they are ever encountered, importing multi-user
Shapes/BlendShapeChannels/etc. as single-users remains supported, e.g.
a Mesh with a BlendShape with two different BlendShapeChannels that both
have the same Shape will still import that Shape as two separate
ShapeKeys.

The code needed for iterating through each type of connection was
duplicated and was getting rather large with the newly added code, so
it has been refactored into calling a generator helper function.

The outermost loop had an unnecessary line of code that would re-get
values from fbx_table_nodes, this has been removed.

The attached .fbx is a default cube with "Move Up" and "Move Down" ShapeKeys added, but I have modified it by duplicating each of the ShapeKey-related connections once. With the old code, this would import 8 copies of each ShapeKey. With this patch, only a single ShapeKey of each is imported.

This fixes the import of hundreds of thousands of Shape Keys when importing the files in #104909 due to their excessively duplicated connections, but the import will still fail due to #84111 because the files contain extraneous FullWeights.

Rarely, FBX files with duplicate ShapeKey-related connections are encountered. The FBX IO addon would add a ShapeKey for each duplicate, however external software appears to ignore the duplicates, or overwrite the existing duplicates such that the same effect as ignoring new duplicates is achieved. This patch modifies the FBX importer to skip all duplicate ShapeKey- related connections when finding the ShapeKeys to add to each Mesh. While it is unclear if they are ever encountered, importing multi-user Shapes/BlendShapeChannels/etc. as single-users remains supported, e.g. a Mesh with a BlendShape with two different BlendShapeChannels that both have the same Shape will still import that Shape as two separate ShapeKeys. The code needed for iterating through each type of connection was duplicated and was getting rather large with the newly added code, so it has been refactored into calling a generator helper function. The outermost loop had an unnecessary line of code that would re-get values from `fbx_table_nodes`, this has been removed. --- The attached .fbx is a default cube with "Move Up" and "Move Down" ShapeKeys added, but I have modified it by duplicating each of the ShapeKey-related connections once. With the old code, this would import 8 copies of each ShapeKey. With this patch, only a single ShapeKey of each is imported. This fixes the import of hundreds of thousands of Shape Keys when importing the files in #104909 due to their excessively duplicated connections, but the import will still fail due to #84111 because the files contain extraneous FullWeights.

duplicate_shape_key_connections.fbx

17 KiB

Thomas Barlow added 2 commits 2023-10-15 05:02:23 +02:00

b2cfaa146d Fix duplicate shape key import when FBX connections are duplicated

Added some comments explaining the different FBX types and their
relationships.

Removed an unnecessary re-get, of the Shape being iterated, from
fbx_table_nodes.

31157d409d Deduplicate shape key connection iteration code

The main loop was getting rather long so its inner loops have been
replaced with a helper generator function.

Thomas Barlow requested review from Bastien Montagne 2023-10-16 05:25:35 +02:00

Thomas Barlow referenced this pull request

2023-10-16 06:38:15 +02:00

FBX IO: Fix error importing BlendShapeChannels with extraneous FullWeights #104956

Thomas Barlow referenced this pull request

2023-10-16 07:20:35 +02:00

FBX IO: Fix error importing BlendShapeChannels with extraneous FullWeights #104956

Bastien Montagne approved these changes 2023-10-16 11:32:04 +02:00

Thomas Barlow added 2 commits 2023-10-18 17:21:30 +02:00

efc15252ef Merge branch 'blender-v4.0-release' into fbx_fix_duplicate_shapekey_connections

54ba8103bd Increase FBX version

Thomas Barlow merged commit 1edbfe9249 into blender-v4.0-release

2023-10-18 17:24:37 +02:00

Thomas Barlow deleted branch fbx_fix_duplicate_shapekey_connections

2023-10-18 17:24:38 +02:00

Thomas Barlow referenced this issue from a commit

2023-10-18 17:24:39 +02:00

Fix duplicate shape key import when the FBX connections are duplicated

Mikhail Matrosov referenced this pull request

2023-10-18 19:11:48 +02:00

WIP: FBX: Preventing import of duplicate shape keys #104939

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Fix duplicate shape key import when the FBX connections are duplicated #104954