Mesh flips when moving IK bone with segments upwards

Hi, so I have been rigging a dragon but something weird is happening on one of the wings, it’s one bone with an IK that has a Chain Lenght of 1 and it works alright when the bone has only 1 segment, but I need to work with 3, that’s the reason of the IK. On the pictures you can see how the wing is behaving normally before reaching certain point and in the second is how it looks like after the flipping, it’a a 180 degree flip and only on the outer segment.

I recently saw the light of the beauty of Blender coming from the dark world of Maya, so I’m still learning the ways of rigging here.



Any suggestions are appreciated

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Ok, this happened on the stomach too, please, someone???
The constrain the root bone has is 50% of position from the left bone and the other 50% from the right bone… But I’m 100% sure that’s not what it’s causing it because it’s the same thing happening on the wing and there were no constraints.

Please! I made the wings FK so the wing isn’t a problem anymore, but there’s no way I can have the rig without root bone or stomach bone. ;-;



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bump :spin:

I’m sorry, I really can’t tell what’s going on from the images you’ve posted. So many things might be off… It might be a good idea to post the blend file for someone to take a look.

Oh, sorry, here it is. If you pull down the root bone it will flip.

I deleted some parts (not needed to see what’s happening) of the mesh because I need to protect the file and who knows who might take it for other purposes.

[ATTACH]364897[/ATTACH]

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Dragon_.blend (705 KB)

I cannot find the root bone, and I think that is the problem. You have a “root” vertex group, which is assigned to the problem part of the mesh, but the bone “Bone” seems to be in charge. “Bone” also has a vertex group.

I’d suggest you copy the file, then delete dragon.001 and backup dragon (if those are the incomplete versions) to clean up the file somewhat. Then remove deformations from the “Bone” or “root”. A Root bone is supposed to move the entire structure, armature and mesh, and anything that cannot be in a bone heirarchy (mainly helper and mechanism bones) is parented to the root, as is the base bone of any bone chains. The root bone should not directly deform any part of the mesh.

Redo the weights so the ‘Spine’ bones move the mesh in question.

Oh, I forgot to name the supposed root bone, and I was calling it root because it’s the center of the spine and if it wasn’t for all the IKs it would move the whole chain, I’ll later on add a bone to move the complete dragon, but for now I’m looking for the thing to actually work. Also forgot to delete those backup meshes hehe (dragon.001). And the spine bones do move the mesh, what are you talking about? o.O

I can’t add it here as an image or attachment for some reason, so I uploaded it to imgur:

Well, you have a vertex group called ‘root’ that seems to include the faces that are ‘flipping’ when you move the ‘bone’ bone. There is also a ‘bone’ vertex group with faces assigned. Since neither ‘bone’ nor ‘root’ should be deformers, I’d start by fixing that problem, which may involve re-doing the weight painting on nearby spine bones.

Aaaaah you are so riiight, the Bone is ticked as deformer…
I unticked that, I deleted the vertex groups from controller bones and it still happens :confused:

This is the second rig I make on Blender, the first being a biped character and following a tutorial, sooo it’s probably another thing like that… I still don’t understand vertex groups very much to be honest.

OMG! you’re going from a biped to a four winged four legged long tailed dragon???

OK. Vertex groups: a set of verts attached to a named group. If the group has the same name as a bone, moving the bone will move the group (assuming the mesh has that armature modifier). Parenting a mesh to an armature can set up the vertex groups automatically, either with no weights assigned (for mechanical models) or with automatic weights (for organic models). You can also set up vertex groups by hand, but with complicated armatures, it’s very tedious and since the bone and vertex group have to have exactly the same spelling to work properly, is prone to errors caused by typos.

Rigging: look for the series “Humane Rigging” from the Blender Foundation or on YouTube.

Most characters put the root bone under the character and start the various bone chains (spine, legs, tail) at the hips rather than the chest. I also noticed you are using Quaternions instead of Euler rotations for your armature. You might try switching to Euler to see whether that helps (although I’m a little hazy on how Quaternions work in practice).

You might want to go back to your working biped rig and put a tail on him (her?) and get that working, then add a single set of wings. Once you get that rig working to your satisfaction, then go back to your dragon.

Hahahahahahaha I’m not a newbie in rigging rigging don’t worry, I could do it in Maya, I’m just learning Blender xD and I have rigged tails before, a warrior ferret to be exact.
And technically it’s a 4 legs, 2 arms, 2 pairs of wings, long tail, 2 jaws badass dragon :stuck_out_tongue:

If I add a tail to any biped character, then it would still have the root bone at the hips, so not much of a difference, his root is not really at his chest but at his first pair of hips. I haven’t seen much about the Quaternions and Euler thing… I have heard it before, Maya had them and I remember seeing Quaternion on the skinning options, but I never really messed with it. Anyways, almost everything on the rig is ready, including the rest of the skinning, I’m just missing some details and this thing happening that flips the mesh. Having deleted the vertex group of the root bone and unticked the ‘deformer’ option on it, is there anything else that might be causing this?

And fingers. Don’t forget the fingers…

Quaternion rotations are designed to get around the problem of gimble lock that arises with Euler rotations. IIRC, one of the segments in Humane Rigging explains how that works. I would give that a try, too. You can always change it back if it has no effect.

The only other thing I noticed is the place where the flipping is happening is right at the point where the spine bones change direction, pointing toward the head or pointing toward the tail. You might try moving the root down to the second pair of hips, and treat the current location as just another set of arms or wings. I haven’t rigged anything with a tail, so I’m not sure how that reversal of direction works, but the spines in my rigs are all one direction from hips to head.

Ah yes, I remember having to deal with that A couple times, having it with wrong axis order would twist my mesh horribly. But now that you mention it… It’s a good idea turning the things in more isles instead of having everything connected, it makes sense. I’ll try it tomorrow, thank you! :slight_smile:

Oh and I’ll also check those videos too, seems like they go deeper than the typical rigging characters tutorials.

It worked! :slight_smile:
Thank you very much for your help!