Today I went to the local library and checked out some CG Animation books to help further my understanding of some of this stuff. Long story short, I still can’t create a simple IKA chain. I mean a simple, 3 or 4 bone IKA chain. Just something simple to see if I’m doing it right. Yes, I’ve gone through the documentation, but I just can’t get it to work. From what I’ve read, the end bone needs to be the IK solver, but when I set my last bone in a simple chain to that, it never responds correctly. Sometimes when I name the bones the “Const” field turns red. I’m still very lost here so any help would be appreciated. And like I always say, feel free to contave me on AIM: Noplasticrobots
Right . . . yes.
I have no idea what you are talking about. 
Post a picture of what an IKA chain.
Then I might be able to help you. 
An IK chain should look just like an FK chain. My problem comes in at the labeling of the bones I think. I don’t know what else I can be doing wrong.
well, understanding the basics of IK is quite easy, but every 3D app has it#s own way of implementing these features. click on the link below (part of the blender documentation) and read carefully to understand the way blender deals with IK chains and rigging.
have fun
http://www.blender.org/modules/documentation/htmlI/x7174.html
I had a bit of trouble with it to begin with because I’m used to using Maya where you select the end points and add an IK handle.
In Blender, do this:
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Make an IK chain and be sure to pose it roughly in the direction it will move in editmode. So fingers would be bent towards the palm of the hand.
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Once you have all the bones, make sure they are all connected. That is, when you move any of the in-between points, 2 bones actually move. This is done via parenting and clicking the IK button. Exact bone naming is not an issue - like you can call a thigh bone a femur or whatever - just make up a system that you recognise or use conventional naming and stick to it.
If you think along the lines of the song that goes, “the leg bones connected to the hip bone” etc. - you should be ok.
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Now, you have to add a null bone to the end of the bone chain. This also has to be joined by parenting & pressing the IK button. It doesn’t matter the direction of this as you don’t use it when posing. I think this is quite confusing. It would have been better if you could use the last bone in the chain but because of the way constraints work, the base of a bone is constrained and not the tip.
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At the same point the null bone joins, you add another bone, which acts as the IK handle. This bone does not get parented to anything unless you have say a finger that moves when the hand does but you don’t. This IK bone should point in such a way that you can select it easily. For fingers, you can point them out the fingertips. Again, the direction is not important.
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Now, you are done in editmode. Switch to pose mode and right-click on the null bone (not the IK bone). Then make a constraint in the object panel (F7). Of course, it will be an IK constraint. You will get a box that says OB: - in here, you enter the name of the armature. By default, this is called Armature. When you do so, you get a box called BO: - in here, you enter the name you gave to the IK handle and hit return. If all goes well, the red box called constraint should turn from red to grey. If not you have named something incorrectly.
You’re done. Just move the IK handle and the bones should follow.
You’re done. Just move the IK handle and the bones should follow.
yeah just have a cup of tee in one hand and move the IK handles as you wish the bons should move and wwaaay…I never knew a joint could move like that… man one can se some strange behavior
to the point
@oxrules u mentioned that you ar used to the maya way. now I would like to keyframe my feet and toes (hand and fingers as well)with fk for more exact movements, but handling the leg and arms with the ik as it saves a lot of hassle(or creates it, when your leg is wrapped around the neck out of a sudden… :-? )
so in theory I just extrude the ancle joint, make it a null bone and add an empty (u said a bone, but it should be the same.)
now my empty is the ik handle and it works out all right, to set frames for a cycle etc., but when I then fk keyframe the feet and toe movements, this is completely ignored when I move the action strip in the nla. and then it starts:
it should work out like this…but it ends up like that (that=complete mess up of odd unwanted movements…but this is another story
so:
can I have fk and ik in the same action, or do I have to blend them as 2 different actions…? (I dont mean fk +ik at the same bones)
is it the right way yo do it?
selec ancle>extrude>selec bone> constraints : null > add empty constraints > ik >name object
click ik for all the leg
leave foot and toe out and blend their movement in with fk keys
%|
hope this is understandable
btw. should this thread not be in the animation forum?
and I think its not the same Q as the title…thread-checking :Z
IK stuff only really works inside a 180 degree area. If you go outside this, the IK joint will flip. It’ll flip more erratically if you haven’t recalculated your bones roll values using ctrl-n before animation. That’s why it’s important to set the bones right in editmode before you bind to your model. One thing I don’t like is that the models bind to the editmode pose and not the posemode pose. This means you have to model your geometry to suit the bone positions for IK and remodel if they’re wrong. If it bound to the posemode pose, this wouldn’t happen.
You may be able to use an empty in place of the IK handle bone but I don’t recommend it because they are harder to select when posing your model. Also, I think you can only add empties in object mode but when you switch to that mode, it uses the posemode pose, which might make the empty quite far from the bone it’s controlling if the posemode pose is vastly different from the editmode pose.
can I have fk and ik in the same action, or do I have to blend them as 2 different actions…? (I dont mean fk +ik at the same bones)
is it the right way yo do it?
Yes, you can have FK and IK on the same model. You can’t have them on the same bones, though. Blender prevents you from moving bones in an FK fashion if they are part of an IK chain.
selec ancle>extrude>selec bone> constraints : null > add empty constraints > ik >name object
click ik for all the leg
leave foot and toe out and blend their movement in with fk keys
%|
hope this is understandable
You select the ankle, extrude a bone. This is the null bone. Make either an empty or another bone - this acts as the IK handle. Go to posemode and select the null bone. Add constraint -> IK and name the armature as OB and the empty or bone as the BO.
If you mean click IK for the entire leg to mean that you join the foot up to the leg with the IK turned on then no. The foot should be the child of the IK leg chain but with IK turned off. I just checked and it seems to mess up quite badly if you do this. It also disables the IK setting on the null bone so that it appears the IK handle no longer functions but you just re-enable it.
btw. should this thread not be in the animation forum?
and I think its not the same Q as the title…thread-checking :Z
It probably should be but it’s hard telling what’s general Blender stuff and what’s not. I wish there were less forum sections because some of the other sections don’t get answers as quickly. Even if there were just 3 or so - Blender General, plugins/scripts and the real-time engine.