Problem with uploading already-rigged characters

[Tidominer]

Hello everyone. I'm having a problem with uploading my character which I already riggedin blender, in mixamo website for animating.
Mixamo can recognize all the bones and everything is good, but the problem is when I use a custom rig, Mixamo shows an additional bone from spine to the armatures origin.

 When I download the model from Mixamo and open it in Blender again, the bone is not there anymore, BUT spine keyframes are applied to the Rig object ,not the bone!

By the way, it doesn't happen when I rig my character in Mixamo but I kinda nee to use my own rig, I would really appreciate it if you have any solution for this. Thanks

[Ussnorway]

Mixamo only works on Mixamo rigs, if your model already has bones then the software ignores it i.e, does nothing

the correct work flow is upload your model [without bones] and download it rigged as a Mixamo model... if you then want to open that model in Blender [or whatever] and add your own custom bones to it thats fine and good luck

[TylerG 3D]

This is actually a commonly misunderstood capability, mixamo actually can retarget to custom skeletons if it can roughly approximate the layout of a bipedal skeleton, even if they have more or less spine joints or less than 5 fingers. In this case though it appears that it is treating the armature object on the ground as a root bone but mixamo's internals use the hip as the root. I've seen some people find success adding the root bone back with this 3rd party plugin, but I can't say it's offically supported or anything https://github.com/enziop/mixamo_converter 

[Tidominer]

I somehow fixed the problem, I changed bone names to mixamo rig bone names ( mixamorig:Hips,mixamorig:Spine , ... ) and I wrote a python script in blender wich changes the names back to normal. When uploading the character with mixamorig names, I still can see the bone from the Hips to the origin in Mixamo but when I download it again the bone is gone and keyframes are applied to the bone. I've been using Mixamo for several years and I didn't have this problem before . (even with my custom armatures). I thought it might be added in an update or something ... if Mixamo still gets any updates ...

[Ussnorway]

if Mixamo still gets any updates ...

By Tidominer

it gets changes