I have a very simple armature. I made the right side by copying the left side and reversing names,
If I copy a pose from the left arm and paste it to the right one, it works fine.
But when I turn on the pose option to “Mirror on X Axis” the thing will not mirror. I have no idea why. Any guesses?
(This is in 2.5, but I threw this into 2.49, and it didn’t mirror there, either…)
Oh interesting… that function is actually an edit mode function, not pose mode. I believe this is the same feature from 2.4x that was found next to the x-ray and auto-ik buttons. If you tab into edit mode the option works. If you disable it in edit mode and go back to pose mode you’ll see that it is now disabled for pose mode as well… this is a little confusing obviously, it probably shouldn’t be visible in pose mode under ‘pose options’ 
Oh… OK. I thought (since it was there) it was allowing for symmetrical posing – which would be useful in some cases.
Thanks for clearing that up!
In 2.4x in the 3-d window there are copy pose, paste pose, and paste flipped pose buttons. Pose a right arm, select all the bones that were posed, hit the copy pose button then hit the paste flipped pose button and the left arm will duplicate that pose.
It works if you are creating a walkcycle, one arm is swinging forward, one arm backward. Select those bones you posed, copy pose, advance say 10 frames and paste flipped pose, now the arms are the mirror of each other…
Randy
see attached pics
Yeah, I got the paste flipped thing… that works in 2.5. I just thought that the Pose option to mirror X-Axis was indicating that it would be dynamic… as I posed on side the other side would follow… but as FeelGoodComics pointed out, that really shouldn’t show in Pose mode.
(Unless development plans to surprise us or something…)
