And this lesson, we're going to fix two issues with the forum, the first one is the same issue is
the need.
When we move the hand, we can see that this bone crashes in through the elbow.
So we need to adjust where the joint pivot is rotating from.
So let's select both of these joints.
And will actually unapparent all of the bones first so that they don't get all wonky and go everywhere,
so I'll hit shift pee after selecting them, which will unapparent them, I'm going to select both of
these joints and I'm going to make sure I'm on the world move manipulator option here and I'm going
to go to skin move skinned joints.
Now we can see we have that tool selected and we can just move this pivot forward.
Let's go to the top view.
Spacebar, left click, top view, let go.
And now we can see kind of relationship.
I'm looking from here to here and we don't want to go on this side of that.
Right.
If I was to draw a straight line from here all the way through to this joint, I don't want this metal
joint to go past that line.
So I need to stay on this top side of that line, that imaginary line.
So I'm going to drag these four just until that point.
And now I can go back and parent all of these up again and test this out.
So we haven't parented, I can select the hand control and you can see it works much, much better and
I think that is a reasonable amount of crashing on this rig to to be able to put up with.
So I think that's fixed that issue.
So the second issue we want to address is the fact that when we rotate the wrist, we select the hand
control here and we rotate the wrist.
The form itself does not rotate.
So take a second and look at your own forearm.
Rotate your wrist.
Right, rotate your wrist.
Just like I'm rotating this and look and feel of what your actual forearm bones are doing.
This is called the radius and the ulna.
And you'll notice that they twist that these two in joints are stuck right there, stuck to the either
end of this hand bone.
And so when they rotate, the hand rotates.
They should stay stuck to the ends of that.
Right.
It twists around each other there.
And they kind of pivot from back here because these stay stationary, but these ends follow the hand.
So let's create a rig that will do that.
So let's think about it.
We need to have something for these to follow.
All right.
It can't follow the hand control because the pivot of the hand controls in between them.
We need something that pivots and or is exactly where kind of the center of these two ends are.
So we need to create something new for that to happen.
So let's create two locators, go to create locator, and we can turn on this little option here.
It says snapped a projected center.
So I'm going to click that.
And with w I'm going to middle mouse drag.
And now that a middle mouse trying, it's constantly trying to find the center of whatever object I'm
middle mouse dragging in.
So I'm going to try to get it somewhere towards the end of the bone here.
And I think that's good, I'm going to duplicate this and I'm going to middle mouse drag into the top
center of this bone and now I'm going to name those.
Radius, aim, actually, and ulna.
Aime.
And I'm going to parent those under the hand control here, so I'm going to select that and happy.
So now when we rotate this, we have two pivot points.
Let me just turn off the polygon so you can see we have two pivot points here that rotate with the Hanken
that are in the center of it.
So that's very helpful.
That's what we need.
So now let's take a look at what we can do to kind of get these to constrain just to those points.
If we were to do like an orange or a pair constrained, that's going to do the entire bone.
And we don't want that.
We just want it to pivot from this end back here and we can turn off this Synthroid snap thing.
Now, we want to pivot from back here and point towards those locators.
So we need to learn about a new constraint that's called the aim constraint, and it does exactly what
you would think it would do.
So I'm going to open this up, open the option box and let's take a look at this real quick.
Any time you see three things like this, three empty boxes or three boxes with numbers in them, you
can reasonably assume that it means this is X, the middle one is Y and this is Z.
And you remember that based on the translate X, Y and Z up here, my will always put these in that
order.
Right.
Whenever your.
Kind of seeing it in a dialog box.
Of course, the rotation order that we learned about earlier, that's something totally different and
we can set that order ourselves.
But when you see it in a menu like this, you can reasonably assume this is X, this is Y and this is
Z, even though it doesn't say that here, that's what these three boxes indicate.
OK, so what this is saying is the aim vector is one, it's in the positive X, X, Y, Z.
So this is X..
So if we take a look at the bone and we see which way is pointing positive X, that is the arrow.
The Red Arrow is pointing.
Right.
So that's correct.
We wanted to aim in that direction.
So the default is correct.
The other vector is y positive y this is that's fine by me and that is pretty much all we need to make
sure is oriented correctly.
So let's select the locator first and then the joint and lets it apply.
Now let's do the same for the other.
We'll select the locator and then the joint and had apply.
And now let's rotate the risk on and we can see.
Like, I just get super excited over the simplest stuff.
I love this stuff, we can see that this is actually rotating around each other and it looks kind of
frickin believable how bones rotate.
I just love stuff like this, how you can click a couple of buttons and then you've recreated what a
human does.
So that's pretty awesome.
So the next lesson, we're going to address the head and how we can add a little more expression to
that model.
Thanks for watching.