FBX Known issues & TODO's #68575

New Issue

Bastien Montagne · 2019-08-12T16:10:24+02:00

Bastien Montagne commented

2019-08-12 16:10:24 +02:00

This task aims at gathering and keeping tracks of known TODO's and bugs affecting FBX IO add-on, which are not likely to be fixed any time soon. Feel free to pick any of those if you feel comfortable with that format and want to help improving its support in Blender.

DESIGN's

{icon circle color=green} #72680 (Vertical bar ("pipe" character) in action names on FBX export)

TODO's

{icon circle color=yellow} #75277 (FBX 7.5 file not importing.)
{icon circle color=yellow} #69554 (FBX import does not read custom bone properties )
{icon circle color=yellow} #46019 (Blender fbx does not export normals correctly for blendshapes) - This one should be doable relatively easily, as we should have the needed bits to retrieve that information in Blender RNA code now. Export only though, obviously.
{icon circle color=green} #69408 (FBX does not support smoothing groups.)
{icon circle color=green} #47400 (FBX test suite )

Bugs

Note: Most of those probably relates to two problematic areas, that are currently not well uderstood: FBX handling of scale/units, and (the biggest culprit) FBX transformation model, especially when it comes the parenting chains (children objects, but also the whole skeleton thing).

#77811 (Animation jitter on FBX export)
#77815 (Meshes parented to bones have an offset in the exported .fbx files.)
#76928 (FBX exporter doesn't export Constant Interpolation keyframes)
#76800 (FBX "Automatic bone rotation" during animation import does not work as promised)
#73863 (Spline IK 'Fit Curve' scaling incorrect on FBX export)
#71729 (Lack of null record on Properties70 node by FBX Exporter)
#71670 (FBX exporting - camera pixel size don't correspond to original size.)
#70161 (FBX I/O Imports and exports objects with wrong scale transform)
#69343 (Models exported using the blender fbx exporter do not react properly to vertex displacement shaders compared to the same meshes exported as Blender OBJ's and fbx's from other programs.)
#66180 (Blender 2.80beta - FBX import missing textures + deformed animations)
#63807 (Blender, UE4 via FBX. Don't work root motion because blender make one more root bone.)
#61860 (FBX Exporter: vertices exported in incorrect position causing mesh deformation)
#60111 (fbx: Armature breaks object hierarchy)
#56883 (Incorrect bones matrix calculation when exporting to Fbx)
#54071 ([FBX Import] Wrong scale on imported objects - General multi-level parenting issues...)
#53908 (Fbx export: random, weird bones rotation artefact)
#53620 (FBX Import - Armatures are incorrect)
#51704 (FBX: exported mesh/animation does not work properly in UE4 when exported using 1 metric unit scene scale)
#51633 (FBX: Exported rigged geometry weirdly distorted, looks eaten away at bone positions)
#51533 (FBX: Trouble exporting animation to Unity, looking like Blender's baking problem )
#47344 (Binary FBX (Version 7.3) with parented root bone does not import at all)
#45176 (FBX import - mismatch in camera rotation)
#47043 (Importing an fbx skeletal mesh from Blender into Unreal Engine 4 results in bones being too small to create Unreal physics asset. Requires scaling workaround.)

Unclear Issues

Issues that only show in over-complex files, or from files with unclear origin, etc.

#96179 (Uncorrect FBX import)

This task aims at gathering and keeping tracks of known TODO's and bugs affecting FBX IO add-on, which are not likely to be fixed any time soon. Feel free to pick any of those if you feel comfortable with that format and want to help improving its support in Blender. DESIGN's ------------ - {icon circle color=green} #72680 (Vertical bar ("pipe" character) in action names on FBX export) TODO's --------- - {icon circle color=yellow} #75277 (FBX 7.5 file not importing.) - {icon circle color=yellow} #69554 (FBX import does not read custom bone properties ) - {icon circle color=yellow} #46019 (Blender fbx does not export normals correctly for blendshapes) - This one should be doable relatively easily, as we should have the needed bits to retrieve that information in Blender RNA code now. Export only though, obviously. - {icon circle color=green} #69408 (FBX does not support smoothing groups.) - {icon circle color=green} #47400 (FBX test suite ) Bugs ----- *Note: Most of those probably relates to two problematic areas, that are currently not well uderstood: FBX handling of scale/units, and (the biggest culprit) FBX transformation model, especially when it comes the parenting chains (children objects, but also the whole skeleton thing).* - #77811 (Animation jitter on FBX export) - #77815 (Meshes parented to bones have an offset in the exported .fbx files.) - #76928 (FBX exporter doesn't export Constant Interpolation keyframes) - #76800 (FBX "Automatic bone rotation" during animation import does not work as promised) - #73863 (Spline IK 'Fit Curve' scaling incorrect on FBX export) - #71729 (Lack of null record on Properties70 node by FBX Exporter) - #71670 (FBX exporting - camera pixel size don't correspond to original size.) - #70161 (FBX I/O Imports and exports objects with wrong scale transform) - #69343 (Models exported using the blender fbx exporter do not react properly to vertex displacement shaders compared to the same meshes exported as Blender OBJ's and fbx's from other programs.) - #66180 (Blender 2.80beta - FBX import missing textures + deformed animations) - #63807 (Blender, UE4 via FBX. Don't work root motion because blender make one more root bone.) - #61860 (FBX Exporter: vertices exported in incorrect position causing mesh deformation) - #60111 (fbx: Armature breaks object hierarchy) - #56883 (Incorrect bones matrix calculation when exporting to Fbx) - #54071 ([FBX Import] Wrong scale on imported objects - General multi-level parenting issues...) - #53908 (Fbx export: random, weird bones rotation artefact) - #53620 (FBX Import - Armatures are incorrect) - #51704 (FBX: exported mesh/animation does not work properly in UE4 when exported using 1 metric unit scene scale) - #51633 (FBX: Exported rigged geometry weirdly distorted, looks eaten away at bone positions) - #51533 (FBX: Trouble exporting animation to Unity, looking like Blender's baking problem ) - #47344 (Binary FBX (Version 7.3) with parented root bone does not import at all) - #45176 (FBX import - mismatch in camera rotation) - #47043 (Importing an fbx skeletal mesh from Blender into Unreal Engine 4 results in bones being too small to create Unreal physics asset. Requires scaling workaround.) Unclear Issues -------------- *Issues that only show in over-complex files, or from files with unclear origin, etc.* - #96179 (Uncorrect FBX import)

Bastien Montagne commented

2019-08-12 16:10:24 +02:00

Added subscriber: @mont29

Bastien Montagne self-assigned this 2019-08-12 16:10:57 +02:00

Viktor Balogh commented

2019-08-12 17:14:15 +02:00

Added subscriber: @Max500

ghoulish commented

2019-08-19 22:19:05 +02:00

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item412 commented

2019-08-27 13:27:15 +02:00

Added subscriber: @item412

gobb_blend commented

2019-10-04 20:39:42 +02:00

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Doug Richardson commented

2019-11-16 22:45:18 +01:00

Added subscriber: @DougRichardson

Gatis Kurzemnieks commented

2019-11-20 13:57:10 +01:00

Added subscriber: @GatisKurzemnieks

Juno H commented

2019-11-22 00:51:32 +01:00

Added subscriber: @Darkoxen

Vyacheslav commented

2019-11-23 19:46:06 +01:00

Added subscriber: @Ghostil

Vyacheslav commented

2019-11-23 19:46:06 +01:00

In 3Ds max, animation and rebar from a blender are not correctly imported. I hope someday this will be fixed.

Philip Guin commented

2020-05-28 00:53:54 +02:00

Added subscriber: @Frizzil

Philip Guin commented

2020-05-28 00:53:54 +02:00

I left a comment on https://developer.blender.org/T73863 that may be pertinent to other bugs in this list. TLDR: I cloned Blender and looked into the bug, found out the issue involved FBX's scale inheritance being fixed at "RSrs" instead of accounting for bones' Inheritance Type. More troublingly, however, is that other software packages do not appear to deal with "Scale Compensation" consistently or correctly. Please see the comment for more details.