# How do you align to an axis AND fix bone roles?

When I extruded bones, they became a bit rotated. But, when I hit ctrl+n and align to the global z axis, it makes them all nice and straight, but, they’re bone roles are all the angles it took to rotate them to be aligned with the z axis (random looking). Is there like an “apply rotation and scale” but for bones in edit mode so that they new alignment is the new 0 bone roll?

Bones don’t work that way. They don’t have a location. rotation and scale like an object does. They have a head and tail location, that define a vector, and roll that defines the up axis. For bones to operate like they do, they need a vector, and an up axis. To hide those values under a location, rotation, scale wrapper would be kind of silly. If the bone roll values bother you… don’t look at them.

That seems more like trolling than anything else.

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He’s not trolling you. Bone roll values by themselves do not mean jack squat in the grand scheme of things. Bone rolls mean something, because they determine the direction of the local axes of the bones. That is the important part. If the bone is rolled so the axes are pointing the way you want, the actual roll values are unimportant. Don’t get hung up on them. Axes > Bone Roll Values.

Another way to look at it is this…If the bone is aligned with the world axes in some way, the bone roll values will make sense because they will be reasonable numbers like 0, 45, 90 etc. However, if the bones are not aligned with the world axes like what is common when placing arm bones in a A pose, the bone roll values will be “weird” like 25.333 or something. The important part is which way the local bone axes are aligned so in Pose mode, they make sense for the animator.

I hope that makes sense.

Good luck!

Okay…

Is there like an “apply rotation and scale” but for bones

No…

How do you align to an axis AND fix bone roles?

First you need to be able to see what the axis of each bone and which way it is pointed…
Select your Armature > goto the Properties Panel > Select the ‘Object Data Tab’ (the little man icon) > find ‘Display’ Panel > check the box next to Axes… (should say Axis… but who cares)…
Now when ever your in Edit or pose mode you have a nice XYZ icon to show which way the axis are pointing on your bones

Now the easiest way IMHO to edit the bone axis is you have the Right hand tool bar open press"N" to toggle it on or off …
and find the ‘Transform’ Panel > ‘Roll’ slider… and move or type into that slider to adjust the bone roll…

They don’t have a location. rotation and scale like an object does.

No… I will have to disagree… I’m not at all sure where your getting this idea from… all three of these factors effect bones… each individual bone has a Location, Rotation and Scale Matrix associated with it in the underlaying software… just exactly like Objects do… they could not operate in 3D space otherwise…
And in fact… Bone Roll is many times more important to Bones and Armatures than it is to Objects…

Bones have to be aligned with one another to work correctly…
not paying attention to Bone Roll is the quickest way to achieve Gimbal lock and bone flipping in the middle of an animation… Good Bone Roll Alignment will definitely insure these conditions are lessened if not all together avoided…

I highly recommend that you go watch Nathan Veghdals excellent “Humane Rigging” series…

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