Help with older foot rig tut? Please

In the picture you can see the big bone called IK foot? The tut asked us to add it, but then we never did anything with it.:

Figure 52. Full complete leg rig.

Yet it is shown in use in the following pics:

always be shortcomings.

So how do you hook it to the two locations? I tried constraints from the to null and heel null to it, but then the foot went weird…

The tut is here at the bottom:


OK I built the rig as described … and got it to “work” … though I must say the toes don’t work very well … There are better set ups then this, like this from Calvin’s site : … which is also more up to date with how the constraints panels look and with more current features …

But here it is :

You’ll notice that the IK_foot bone is the parent of both the IK_toes and IK_heel bones . If you grab/rotate that the entire foot will move/rotate . This illustrates one of the most important concepts in armature hierarchy and how you can use that to do things .

Also notice the how the IK Solver constraints are set up - with the “Use Tip” button turned off … I am guessing that the old IK Solver by default didn’t use the bone with the constraint applied (I don’t know for sure since I didn’t start using Blender until 2.42a) …

Oh, thank you again, you have been busy today!

I will look at both. As it is I have the arms from one tut, the hand I did myself, and the legs and feet from above, oh and the spine from another.

Im very confused. As soon as I hit a road block I just go to another tut for that section…thinking I will get it or that its a finished tut.

I thought since this was the old one, it would be finished, but he forgot the foot ik…I know I should understand enough now to figure it out myself, but I really dont.

This has been hard for me to learn, I think its my dislexia. Too many different names(bones) and contraints/copy location etc…the words tend to loose all meaning.

Then I stop for a while and im just so stubborn, I try again.

I had been turning off use tip and stretch. Its interesting. When I first turned it off the arms, the the hands went limp, but after moving them a bit, they bounced back to taught again.

Might be my machine… some odd things have been happeing in the last couple days, like missing files etc. Im sure its not the operator but the cumputer, lol.

Ps. I havent used the rest postion button yet. Can I specify what rest position to use? I guess I can try it…

The bones that start with IK_ are designed to be animated in positions and rotation. The idea is that you just position them, and Blender figures out what to do with all the other bones to make that chain bend the right ways so that the children/dependent bones (two in this case) can be where the IK_ bone says to be.

In those other pics I think he is showing how moving the different bones moves different parts of the rig, like you can move the IK_Heel, for example. In testing the rig, moving the IK_Foot should move basically all the bones (but only rotate the thigh bone), just as if someone grabbed your foot and moved it around (hopefully giving it a massage).

Hmm, yes I am kinda getting that…but why have that null, bone?,Just to point it at the ik constraint?

and why does the bone, like the toe bone have to have the copy location of the ik constraint?

Why would you want to copy the ik solvers location?

OH, the null bone is the end of that chain, and its only used for the ik solver to start working at that point… and AND, you could have used the bone itself, however its much easier to grab the ik solver which can be positioned anywhere its easy to grab?

But still what about that copy location stuff?

And another question. Are there any docs teaching how to use the x,y, z rotation controls? I mean how do you decide on how far a bone can rotate? For humaniods.

And does that rotation start at zero, from the resting point of the bone?

You need the copy location constraint because neither the toes or the foot are not connected to anything . If you tab into Edit Mode with either the toe or foot bone selected you will see that in the Armature Bones panel the “child of” field is blank . By copying the location of the IK target bones the foot and toe are kept attached to the leg if you only move/rotate the IK_foot bone .

This type of leg/foot rig was designed to let you animate the upper part of your character without having to worry about where the foot might slip . The trick to doing that is to assign an IK solver target that is outside the parenting hierarchy of the rest of the leg and so you get parts that are not directly connected to the leg itself . But to keep unconnected parts still “connected” when you move the foot or the upper leg, you need to use the copy location constraint to keep everything together .

Yes the null bone is the start of the chain . But it has nothing to do with grabbing the IK bone or positioning … The tutorial is somewhat outdated … apparently back then the IK solver couldn’t be configured to use the tip itself to start the IK calculations (as it is now and also default behavior) so you had to add a null bone to add an IK solver .

And BTW apparently (on the subject of additional target bones) in the next release you will be able to target either the tip/midpoint/root of your target bone for all constraints . Right now if you want to target the tip or the middle you have to add a target bone for that purpose because the default is to target the root tip (a bone’s “center” in rotations)

No there are no specific animation criteria for how far you can rotate any particular joint … just rotate them to where your mesh deformation looks good and makes sense .

Yes . But the rest position in Pose Mode is always set to zero even if you have rotations in Edit Mode to set up your armature .