Warning : Gimbal Lock Exist error after changing mesh

[Anonymous]

Hi guys, I've looked at the similar issue on this forum and some other but couldn't find right answer for me. 

I have fully rigged model which works super in MOBU but I want to chenge it's head, after doing this I am getting 

Warning : Gimbal Lock Exist.The FBX file format cannot represent the transformation of some nodes in the scene due to the limitation of FBX SDK. To avoid this, adjust Bone binding matrices of the problematic Skins. 

I already tried to change units when exporting like someone suggested and to copy and paste back skin modifier after changing the model's head.

Any help would be really appreciated (it's for my work placement... ). 

Cheers guys! 

[Anonymous]

I am attaching the file I am working on

[ads_royje]

Hi @Anonymous,

first, thanks for the file sharing! That helps a lot to figure out the issue!

So the error you are getting is related to transform matrices to be scaled, the fbx file format will trigger an error always when a transform matrix is scaled.

This is to avoid any problems with rotation, as rotation and scale are intimately related to one another inside a matrix.

To fix this, you will need to reset the scale of all objects (bones and mesh) back to 100%.

To do this you will need a few steps.

> All explained visually in the attached video so you can follow easier than just text.

For the Mesh :

. with the Mesh selected

. in Skin go to > Advance Parameters

. turn Always Deform to Off (this deactivate Skin modifier)

. keep mesh selected and go in Utilities panel and use Reset X Form

. Go back to the Modifier Stack and move the Reset X Form modifier below the Skin modifier

. right click on the Reset X Form modifier and do Collapse To

For the bones :

. select all the bones in the scene

. in the Animation menu > bone tool >  Object properties

. Set Bone On to > On

. press the Reset Scale

. you may revert Bone On to > Off if you wish too.

reselect the mesh go in the Skin modifier and reactivate Always deform.

You can now export to fbx with out any error.

I hope this can help you go forward! 🙂

[Anonymous]

Thank you so much @ads_royje ! Especially for the video it was really easy to fix the export error! I really appreciate your effort.

However, I must ask you another question, when I am using my original file ***Basic_Female_Avatar*** attached to this post... I can see the skeleton in MOBU so I can easily characterize it, however if I open same file in 3ds Max and export it back to .fbx and re-open in MOBU, all the bones are missing, I can only see the effectors (like on attached screenshot).

Would you able to point me out what am I missing while exporting from max? 

edit: I checked "Convert deforming dummies to Bones" which gave me some sort of skeleton in MOBU but it's not rigged like original file and I feel it's not the right solution. 

best regards, 

Karol