Bug #932

Problems opening FBX format in MotionBuilder 2012 or 2014

Added by Paxalot (Forum User) over 3 years ago. Updated almost 2 years ago.

Status:NewStart date:07/15/2015
Priority:NormalDue date:
Assignee:-% Done:

0%

Category:FBX
Target version:MakeHuman 1.1.2

Description

When I attempt to load the exported FBX MakeHuman file into either MotionBuilder 2012 or 2014 I get the following message:
This version of FBX is not supported. Use FBX converter.

So I use the Autodesk FBX converter to convert to FBX 2012 or FBX 2013
Then the new converted file opens in MotionBuilder.

When in Motionbuilder 2012/2014 when I attempt to characterize the (Autodesk FBX converted) MakeHuman rig I get the following messages:

Geometry warning:LeftUpLegRoll is 2.87 degrees away from it's roll axis
Geometry warning:RightUpLegRoll is 2.87 degrees away from it's roll axis
Geometry warning:LeftArmRoll is 3.87 degrees away from it's roll axis
Geometry warning:RightArmRoll is 3.87 degrees away from it's roll axis

The skeleton does not characterize.

fbx-import.png (16.4 KB) Thomas Larsson, 07/17/2015 09:09 AM

MB2015-import0001-0132.avi (2.57 MB) Rob Baer, 07/19/2015 01:27 AM

screenshot_3_1437262106.png (305 KB) Rob Baer, 07/19/2015 01:29 AM

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Related issues

Related to MakeHuman - Bug #958: Skeleton-handling and Scaling struggle with FBX Export & ... Rejected 09/26/2015

History

#1 Updated by Rob Baer over 3 years ago

Could you tell us what version of MakeHuman this problem occurs with? Is it the release MH version 1.0.2 or one of the nightly builds?

Also, did you export as ASCII FBX or binary FBX?

I ask, because I think the current nightly builds are tagged, "FBX SDK/FBX Plugins version 2013.3" which sounds like what you are converting to with the Autodesk converter. Thus, I would expect it to work in Motion Builder. The current nightly builds, do allow binary FBX export, but it still has some issues, and you will find the ASCII export more stable for the moment.

#2 Updated by Thomas Larsson over 3 years ago

A serious problem with the FBX format is that it is undocumented and changes from year to year. The FBX exporter for MH was created by reverse engineering the output from the AD FBX converter 2013, and may well be incompatible with other versions of FBX.

I presume that you use the development version of MH and tried to export either the Motionbuilder rig or Motionbuilder full rig, since these are the only rigs with these roll bones. However, I cannot reproduce the problem since I don't have access to MotionBuilder. The exported file can be viewed with the free FBX converter; it looks good and there are no warning or error messages. After conversion to binary FBX the file can also be imported into Blender, but the result is less satisfactory, cf picture.

What I did notice was that the .mhskel files for these rigs have hardcoded roll values. Perhaps there is some inconsistency between these values and the definition. However, the roll values are not exported to the FBX file, so I don't seen what could go wrong, nor why the problem only appears for these four bones. Anyway, since the mhskel files are not my code, I will unassign myself from this bug.

#3 Updated by Rob Baer over 3 years ago

r1958 and Windows 8.1

Okay I exported the MH character in default slider position with the T-pose set and the with the motion builder full rig. During export I used decimeter and ASCII with my FBX export.

I opened the file in Motion Builder 2015 without any problems or errors (I don't have older Motion Builder). I had no need to use FBX converter for import.

I dragged "character template" onto the hip to "characterize" and saw warnings for LeftUpLegRoll, RightUpLegRoll, LeftArmRoll, and RightArmRoll as did OP. However, my angles were different than OPs (see figure).

I ignored the warning in each case. I then merged the punch animation from the Motion Builder tutorial folder. The result seems reasonable, even if not optimized (see screen capture- http://bugtracker.makehumancommunity.org/attachments/download/1071/MB2015-import0001-0132.avi)

The Motion Builder 2015 biped is shown in Gold. The MH "motion builder full rig" is the thinner silver skeleton within the mesh.

#4 Updated by Thomas Larsson over 3 years ago

OK, I think I know what the problem is. MB probably assumes that the two bones that make up the left upper arm, LeftArm and LeftArmRoll, are perfectly lined up, i.e. the shoulder, middle of upper arm, and elbow joints lie on a straight line. There are no warnings for the forearms and shins, because they seem to be lined up - elbow, middle of forearm, and wrist joints do lie on a straight line.

If this is the correct interpretation, it is really an incompatibility between the MH default rig, from which all other rigs are derived, and MotionBuilder.

Incidentally, Blender's Rigify makes the same assumption. It creates two deform bones for each of the arm and leg bones, and moreover the two pieces are not only aligned but of equal length.

#5 Updated by Jonas Hauquier over 3 years ago

Thomas Larsson wrote:

MB probably assumes that the two bones that make up the left upper arm, LeftArm and LeftArmRoll, are perfectly lined up, i.e. the shoulder, middle of upper arm, and elbow joints lie on a straight line.

Interesting, I did not evaluate the rig for this quality.
If this is a feature that is necessary in many pipelines then we should find a solution for it.

#6 Updated by Rob Baer over 3 years ago

  • Related to Bug #958: Skeleton-handling and Scaling struggle with FBX Export & Blender Import added

#7 Updated by Aranuvir # almost 2 years ago

  • Target version set to MakeHuman 1.1.2

Does this problem still exist?

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