So I have been aggressively trying to learn blender. After creating several 3d models I’m now attempting to rig them for animation but I’ve ran into a wall that I can’t find any fixes for. I found that the local axis’ for the bones are becoming scewed when I scale them across the X axis (attempting to mirror L/R sides)
Everything looks like it’s going ok… upto the point that I try to normalize the axis’ orientation to match on both sides. One tip I received was to select one side > check the X axis mirror option for the armature > hit ‘G’ and esc which supposedly flips the axis’… only it’s not working.
Here is what happens when I do that…
I desperately need to figure this out, I can’t effectively weight paint or move forward until I get the axis to function properly on both sides! Anyone know a legitimate way to mirror the armature w/o the axis getting flipped/messed up?
Couple of ways to do this, but first a warning. Blender has a copy pose & paste flipped pose function, basically it allows you to copy the pose from one side of the armature over to the other side. Very useful when creating walking actions or any other action that you want to be symmetrical. In order for this to work you bones must have matching suffixes, leg.L - leg.R, arm_L - arm_R, etc… And secondly, the bone’s z-axis must match from left to right sides, if the left leg bone’s z-axis points forward, then the right leg’s z-axis must point forward as well…
Anyhow, ctrl-n (while in edit mode) will bring up the calculate bone roll options. For arms of a character standing in a t-pose (arms outstreched so the body looks like a t), you can select all the arm/hand/finger bones and ctrl-n -> z-axis and blender will adjust all bones so their z-axis is pointing upwards. For the legs, you can do the same thing, but you might need to choose another axis to get the legs z-axis to point forwards. Of course, using x-axis mirror, you only have to adjust one side, and the other side rotates with it. If you have one side of the armature bones rotated how you want them, you can select a bone from the other side, shift select a bone from the correct side, and ctrl-n -> active bone. The first bone will rotate to match the second bone you selected. You can also select all bones on one side, turn on x-axis mirror, and do a ctrl-r to adjust the bone’s roll angle with the mouse, then esc to cancel and the other side will match the selected side, (just thought of this and it might be what you are thinking of when you mentioned using the g-key).
Note that the bone roll has been a bit troublesome, I reported a bug recently and after a bit of communication with the dev, I’m left with the impression a dev needs to spend some time on this.
Have you tried Rigify? It’s pretty amazing.
I’ll second the motion for checking out Rigify, even if you ultimately want to build your own rigs from scratch. Along with that, get Nathan’s Humane Rigging tutorial DVD (he can provide you with a download link once you buy so you don’t have to wait for the mail).
Between these two, you’ll learn so much about rigging your brain will overflow out your ears and become an entity unto its own. You’ve been warned!
Thanks for the help guys! I have rigify but before I use it I wanted to understand what it was doing exactly
@revolt using ctrl r while selecting one side with the x axis mirror on wirked! Thanks for the tips!
Just in case anyone else has an issue like this… here is what I discovered.
When I created the rig I started with the legs and started from scratch. By doing so the object origin point started off center. After flipping the rig to the right side and flipping the names as well. If you try the X-mirror with the origin point being off center blender will attempt to mirror the rig across the origin point’s x-axis, not the x-axis of blender. Totally a mistake only a novice like me would make, but it’s possible someone else out there might stuble across this issue and have a hard time figuring it out as well.
The solution is to center the origin point to the courser or some other point that is centered along the x/y/z axis (or centered on the object you’re creating the rig for) BEFORE you flip the rig.
Yup, it’s always best to Snap Cursor to Origin before adding an armature. If you’re building from scratch, add a Single Bone.
IMMEDIATELY switch to Edit Mode so the armature origin stays at exactly 0,0,0.
I keep telling everyone about this, but I’ll mention it here too. You might consider buying the Humane Rigging DVD from the Blender Foundation store. It’ll give you a really good understanding of how rigs are designed and built. Nathan’s goal with the DVD is to help people get to where they can solve rigging problems for themselves and I have to say, he does that in spades.