Bone Head and Tail Locations Not as Indicated by Transform Location Tools- Solved!

In the above picture I have the armature in Edit Mode with the bip_body bone selected. I have drawn lines on grid lines in the quad view… Looking at the head and tail locations and the bone roll, this bone should be straight, but it’s not. I have manually made sure that the X and Y transform locations are exactly the same and the roll set to 0, but the bone did not move from being offset. I have also made sure that there are no animations or poses on the bone.

Am I doing something wrong here?? I’m working with an armature that was very poorly created here and I’m trying to fix it, but the head and tail X/Y transforms of the selected bone are definitely not were I expect them to be according to the transform info displayed in the tools.

This is the result I get if I place the Cursor on the head and use S shift Z on the Cursor to line the tail with the head.

The logic dictates that X/Y values should be the same, but they aren’t…

I’m kind of lost here, what is going on?

I’m using Blender v2.81.16 (Steam Install)

Is the Armature object itself rotated? Perhaps you could upload a .blend with just the Armature so we could look at it more closely?

hehehe, this was a really poorly put together armature. The OP has no idea what they were doing. I mean, when they put the model together, they had 14 armatures, each of the armatures only had 1 bone and all the bones were named bone. The mesh was glued together using vertex groups made up of mesh objects and bones. Like I said a mess…

Now, what I did was rename the bones in each armature to what they should be, this allowed vertex groups associated with the bones to be automatically renamed to the new bone names. I then unparented the mesh objects. Once the unparenting was complete, I selected all the armature objects and joined them into one armature and then parented the bones into a proper armature hierarchy…

This is the new armature and bones only. I haven’t moved anything from their original postions.
crimson3_bones.blend (1.4 MB)

The model wasn’t properly aligned when the OP started adding bones, so yes, there is some twisting, but I’m not concerned with rolls at this point, I’m trying to get my head wrapped around why the head and tails at reporting different X/Y locations than what they should be.

Again, this is not my armature… I just want to make that clear… This is the type of armature I build…


making an armature with independent bones is not the way to do a working rig !
so I’m giving OP a tut on how to make basic rigging armature
from which he should be able to learn all the steps needed to make a working rig.

learn how to build a basic rig

happy bl

As I suspected, the Armature object itself has some rotation on it, which is why the points in the armature don’t align in the world while being aligned locally. I guess apply rotation on the Armature?

Thanks @RickyBlender ,
That’s what I’m trying to do for the OP as well. Making a video on how to recover from this mess and make it work. The first part was on proper rig assembly and using their model as a test bed. The video took 1 hour and 40 minutes to explain how an armature works, fixing it, then reassigning the vertex groups to use the bones and a bit on weight painting and weight blending between bones.

I was in the process of going on to fix the armature in Edit mode to make it work better in pose mode so it would be easier get the twisting out of the model and get the mesh back into some sort of properly aligned A or T Pose when I discovered this inconsistency. I’m not sure why I’m seeing what I’m seeing from the location data.

@Stan_Pancakes , possible, like I say, they tried to rig a posed OBJ type model I think, so there is going to be twists. I’m starting to wonder if I should have applied transforms to everything before joining the armatures together. That could be part of the problem, but, if a bone head says it’s at location X,Y,Z in both Global and Local mode, and the tail says the only difference is I’m this far away on the Z, (the X and the Y locations are the same), I don’t see how the bone can be tilted like it is. It should be absolutely straight up and down the Z, not offset like this one is… especially in edit mode (when everything should be in it’s rest position… )

I may even try this in 2.79 to see if there’s a difference. I’m completely mystified by this.

only note I would make is that correcting a badly built armature is an advance project and must know all the little commands for armature and bones

so I think it might be easier to simply rebuilt a new armature following the basic tut for rigging
should be faster and easier to do and understand !

have fun with blender rigging

happy bl


Yup, Agreed and when I first was given this model, that was my first thought. Rebuild the armature and pass it back, but there’s no learning in doing something like that. The OP has followed my instructions and the armature on their end is to par with my current fix.

@Stan_Pancakes I am an idiot, I totally missed what you were saying in both your posts. I’ve been so rapt with this problem I’ve been sitting in edit mode. The OP sent me back a screen shot with the armature in Object mode and You’re RIGHT, the dang thing is rotated at that the Object level. I should have caught on with your first response… I was only paying attention to Edit and Pose modes. DOH, DOH DOH x32 Zero the Rotations and that current main bone straightens out the way it should.

Thank you both for your input. I can continue now with the next video now. Much appreciated.

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Just to give you some idea what I started with and where I plan to get to…

This is the model that was handed over to me.

and now that i know what is going on, this is what that armature and model will look like after the video is finished. I think the OP will be pleased with the results they are going to create on their own…

and be able to do this with it…

Again, thanks for the assist in getting my head straight…

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