Hello. I’d like to ask your help understanding the arm rigg, with the elbow controller. In 3Dsmax, it was called up vector.
i did these tuts:
(actually this link is for a list of videos, and did all of them up until this one)
All about an arm rigg. Got it stuck on the elbow
Until the hand IK (including), it all works as expected: th IK is a child of an object, that also is parent of the root bone; the IK is applyed to the last bone, before the hand. It works
Now i want to have an elbow controller… and it went to shit. Made this elbow bone parent of the same root object, applied IK to the bone after the shoulder, with chain length of 1. Although the constrain gets applied, rotating the arm, it distorts the default pose. 2 images as refference:
I don’t actually set it up that way myself. But I just tried it. And it works fine for me. Applying ik to the upper arm does seem to have less in the way of discrepancy between pose and edit mode for the armature. Although in practice it doesn’t seem to have an advantage that I’m aware of, over using a pole target, apart from that.
Without a blend file though, it’s hard for me or anyone else to know what’s actually happening at your end.
I just specify that control bone as the pole target in the ik constraint for the forearm. Then make corrections to the angle if needed, so the resting pose in both edit and pose mode, match up.
What’s the chain length on your forearm constraint?
tried your way:
1 - remove ik from arm, lower arm remais as is: chain length = 2. Then added to lower arm:
2 - pole target = armature, bone = cotovelo_IK.L (lower arm), pole angle = 0
Now the elbow ik works (so the arm bones rotate in the Y axis, that is an axial rotation), but the arm wont bend, no matter how i move or rotate the hand IK
Ok. If your ik chain is not solving then you do need a slight bend in the limb. With the elbow pointing in the right direction. So bring the joint back slightly in edit mode. This gives the solver something to work with. Having a slight bend in a chain always works better, even when key framing. Having a completely straight rest pose for your limbs will cause problems. And it’s not a very natural position for them to be in anyway.
As I mentioned that follows on into animating. Try to keep a small amount of bend in the limbs. If they fully extend on any particular key frame, you’ll get a snapping motion as the chain rushes to the locked out position.
There’s often some discrepancy between edit/pose modes once constraints are in place. I’ve never found it a hindrance to animating though.
well, with that bend this rigg works sort of works, because that discrepancy is bigger than i expected. If i find a better way, i’ll post here. What pisses me the most, is that i can’t duplicate the results of the video tutorial.
I can’t tell you why there’s a pronounced difference in your rig between edit and pose mode. I did however notice it in the video. It’s quite small, but it’s there. To my eyes at least, there is a slight bend towards the target after the ik constraint is placed on the upper arm. Like I said though. It’s really only an issue if it’s interfering with your ability to use it effectively. How it looks isn’t the main concern.
If there was a marked difference between what you see in pose mode, while the rest pose is enabled, that might be more concerning. But it seems to be fine. Don’t forget to switch back to pose mode for animating.
