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Maniphest T40853

New FBX exporter: Animation scale axes mixed up on export to UE4
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Description

System Information
Windows 7, NVidia GTX 780

Blender Version
Broken: 2.71 official release

Hi Blender developers,

thanks for working on the FBX exporter (presented here: http://code.blender.org/index.php/2014/06/supporting-game-developers-with-blender-2-71/) recently!
It's working great so far, but i noticed a (probably minor) issure, it seems to mix up the scale animation axes of my little animation:

Blender:

UE4:

(Both images should be animated GIFs, if the bug reporting tool makes them static as it appears in the preview, I'll upload them elsewhere)

The settings I have used:

Blender Source File:

TorusAnimation.blend599 KBDownload

Please let me know if you need further assistance!

Event Timeline

Nils (_nils) created this task.Jun 28 2014, 6:26 PM
Nils (_nils) raised the priority of this task from to 90.
Nils (_nils) updated the task description. (Show Details)
Nils (_nils) added projects: BF Blender, Import/Export.
Nils (_nils) edited a custom field.
Nils (_nils) added a subscriber: Nils (_nils).

I just noticed: Probably you already know, but the animated GIF files will work when you click them.

Bastien Montagne (mont29) claimed this task.Jun 28 2014, 6:36 PM
Bastien Montagne (mont29) lowered the priority of this task from 90 to 30.

Can you please attach also the FBX file produced by Blender?

Also, I see you used 'Apply transform', can you try without it and see whether it works OK? I would suspect some mess in this area (really complex stuff tbh :/ ).

Bastien Montagne (mont29) edited projects, added Add-ons (Community); removed BF Blender.Jun 28 2014, 6:38 PM
Nils (_nils) added a comment.EditedJun 29 2014, 12:49 AM

Hi Bastien,

I wasn't expecting such fast processing, thanks a lot! :)

Disabling "apply transform" didn't change anything noticable.

These are the two FBX files generated with and without "apply transform":

TorusAnimation_with_ApplyTransform.fbx38 KBDownload

TorusAnimation_without_ApplyTransform.fbx38 KBDownload

Also, I just noticed UE4 complains quite a bit about "bone transform is different from original" in its log, probably that's a hint for you:

UE4Import.txt39 KBDownload

Best Regards,
Nils

Bastien Montagne (mont29) raised the priority of this task from 30 to Normal.Jun 29 2014, 8:32 AM

Thanks for the files, will have a look at that asap.

Bastien Montagne (mont29) changed the task status from Unknown Status to Unknown Status.Jun 29 2014, 10:58 AM

Hrrrm… Those files import back correctly in Blender (with wip version of FBX importer, which now supports armatures & animations).

I assume you are sure about the target system orientation (i.e. -z forward/y up is the native UE4 orientation)? Else, it could simply be UE4 importer failing to convert animations across orientations…

LogFbx:Warning: (3) BindPose - Incomplete BindPose [nodes parents] : The following parent and/or ancestor node(s) is/are not part of the BindPose definition. (Armature.001Armature)

I don’t think this should go in BindPose, it’s a Null model (sort of empty), not a LimbNode (aka bone) one… Can’t be sure of anything here, though (as always, no specs available for this format). I even think (but again, it’s only deductions from my part, no official doc again) that BindPose stuff is deprecated (it has only redundant info compared to Deformer nodes, with less possibilities, at least).

LogFbx:Warning: IMPORT TRASNFORM ERROR : Bone (Armature_001|Bone:0)
Source Global Transform (1.000000,-0.000000,0.000000|0.000000,-0.000000,90.000008|0.500439,1.000000,0.500439),
Converted Global Trasnform (0.000000,0.000000,0.000000|-0.000000,0.000000,90.000015|1.000000,1.998246,0.500439)

I do not know what this means… If 'source' means org data from FBX file, and 'converted' means data in local space, then it sounds like a conversion error from UE4.

For your info, Unity imports those files correctly too. So I’d suggest contacting unreal team, imho the bug is on their side somehow. Will close the report for now, we can always reopen in case it’s needed.

Nils (_nils) added a comment.Jul 9 2014, 11:17 PM

Thanks for your analysis, the UE4 team acknowledges that as a problem on their side and will provide a solution.

Eric Ketchum's reply is buried somewhere in the comments at https://answers.unrealengine.com/questions/20832/epic-official-fbx-import-reporting.html , unfortunately there's no direct link.