Hello, this is Minyong Lee from Anijak Corporation
Last time, we first looked at the character modeling
and the basic process of rigging for character animation
This time, we will take a closer look at
Spline IK,
which is often used in cartoon-style animation
And we'll take a look at the character rigging
made by using that
Finally, we will look at
Finally, we will look at how these characters should be prepared
as assets like backgrounds and props in production
Spline IK & Twist
Now after FK and IK, it's time to learn about
Spline IK, which is used the most next to those two joints
Let's create some joints so we can rig an IK spline
I clicked on Create Joints, and I'm in the side view right now
So one, two, three, four, five
I think this is about enough
So there's six joints
And because Spline IK is based on curves
specifically the NURBS curves in Maya
I should create a NURBS curve as well
And to make the number of vertices on the NURBS curve and IK joints exactly match
to make it easy for the controller later
One, two, three, four, five, six
So now we have six joints on six vertices
And a NURBS curve, based on those same vertices
Now with the curve and joints we created
let's try creating a Spline IK
Like this
As you can see, if you click on Reset Tool
Auto create curve will turn on,
which could automatically create the curve for you
But to make sure the curve's vertices match those of the joints
I manually created the curve
So let's create a handle
after turning this option off
And now there's ikHandle1 on the Outliner
Unlike IK rotate plane solver, the one we used for the arm
You can't just move the joints to create movement
In this spline solver
movement is created
using the vertices of the curve
So it's good for creating very natural and organic movements
But as you move these vertices
the joints might not be able to follow
the entire length of the curve, which you can see now
To solve this, you can add a setting to add joints
To do that, you have to know the length of the curve
The tools we're going to use are almost the same as before
They're the same as IK and FK
So we need to know the length of this shape
The shape of the curve
I'll type in 'createNode'
and summon a node
called nodeinfo
Now connect the length of the curve shape
and the inputCurve of this node
to find out the curve's length
Now I'll connect worldSpace to inputCurve
and now I can find out the length of the curve as seen in the world coordinates
Now if I open the Connection Editor
You can see arcLength is in curveinfo1
So the length of this curve
and the length of the joints will now be connected
To get some more visualized information on joint distance
And turn on Local Rotation Axes
from the Transform display
to see how the local axis is flowing in the joints
Of course if something like phrase transformation occurs
the direction of the axes can change
But in Maya, by default if you draw some joints in the viewport
You will see that the joints' axes by default align with the x axis
In this example, I haven't modified the joints
So they are also flowing along the x axis
I will now connect the arcLength value to the x axis of the joint
So now I am taking arcLength
so the length of this curve, to the other 6 values
Connect to translateX
And now that is done
The curve length seems to be 10 But now that I connected it to the x coordinates of joint 2
the joint just shot out Which is not what we want, so why did it happen?
The entire length of this arc
consists of the joints, which evenly distribute along it
So we now have to divide the arc length
between the remaining joints
So we now have to divide the arcLength value
Type in 'createNode multiplyDivide'
This is an operator that literally multiplies or divides
Now let's establish a connection again
Between curveLength and this x value, which is 10
Now what do we divide that value by?
Because there are six joints, there's five spaces between them
So we should divide by 5
And there's no change in the viewport yet because the output still has to be connected
So now let's take outputX
and connect it to joint number 2's translateX
Oh, the value became 50 And you can see the joint moved even further
The multiplyDivide node should be set to Divide, not Multiply
Now the node should divide the value
Let's check if that's the case
The input value in joint 2 is back to normal
So we have got the length value, divided by the number of spaces between joints
And connected that value to translateX of joint 2
And the same should be done for all the remaining joints
Now the joints look as they did before
But now if we move the vertex
The joints will elongate
And if you look at the value
the value increases as the joints elongate, allowing the joints to stay in a better position
The IK Spline solver has a cool function which is the ability to twist joints
Like you would twist your hip or arms So let's take a quick look at that as well
First set a standard using Creator>Locator So create locator1 and locator2
And place them at both ends of the joints Now this IK joint is like the spine or arm of a person
and we can animate twisting motions very smoothly
If you take a look at the IK handle, which is closed right now
And click on Advanced Twist Controls, below IK Solver Attributes
The axes will get weird, but we can ignore that for now
The most often used options are Object Up and Object Rotation Up
For arm joints you would use Object Up
Let's take a look at that first
How did the joints look before?
The joints were aligned along the X axis
And the Z axis of the joints were aligned with that of the world's
I slightly offset the locators' Z coordinates
To make it easy to see
So Object Up within Advanced Twist Controls
And if you want to set the joints' directions
so that the Z axis is the up direction first set the locators' Up Axis
to Positive Z
And also set the World Up Object
to locator1
and locator2
Then the joint local axes are now set
to the same direction as we drew before
And now if we try to move the joints sideways They will twist like this
So now for example, the joints were aligned to somewhere such as an arm
you can create a very smooth depiction
of the arm twisting
In the other hand, if you were using this to animate someone's hip twisting
Let's change the setting to Object Rotation Up which will mess the axes up again, but ignore that for now
Now place the locators where they should be
and as we did before
change the Up Vector to the Z axis
And it should change like this
so now it looks as it did before But what controls the rotation is not the translate value
But the rotation value, like this
This is a very useful tool, depending on how you use it
This can be used for a large variety of body parts such as the tongue, arms, or hips
Which is why it's often used in rigging
So now let's take a look at how
the IK, FK, the switch between them, and the Spline IK
are used in actual character rigging
This is the character I had finished last time Let's take a look at how it's rigged
I'll hide the polygons so we can see the rigging better
If you see here
this is the IK Spline solver
that we just learned about, and it's being used on the hips
While also being bound to this FK joint
And for the hands and feet, almost all characters these days
and most old characters, are set to switch between IK and FK for those
And over here you can see once again
There are still some hidden rigs If we take a closer look we will see
that there's another IK Spline solver added here as a module to the hand and foot joints
Why don't we take a closer look?
The IK Spline solver can be used
to create some very bendy, cartoonish movements
In this case, I rigged it so that it could go even further and made the arm so that it can stretch
So you can see that even with just
the IK, FK, switch, and the IK Spline solver
you can create these useful riggings
Production Assets
Before this, I talked mostly about some stiff technical stuff
But from now on, we're going to learn about more easy and fun aspects
So you can take your hands off the mouse and just have fun watching
From the perspective of the animator, who has to provide the modeling and rigging of a production asset
it is very important that you understand perfectly the storyboard and animatics, that you have learned about
So this is part of a project called Skull King(스컬킹) and it's only a minute and a half, so let's watch it together
and after that I will tell you which parts I found important
A soldier was cleaning this room when he heard a sound
and a stamp falls from its place
Then the hysterical Skull King enters the room
And he grumbles as he sits down
which he immediately regrets And now the stamp has impaled the desk
So you can see that when creating the desk asset
you have to put a stamp-shaped hole in it
And when the king sits down
it would be fun if the desk would jiggle up and down a bit
Because there's a cut in this angle, there can't be any flaws in the modeling
And after that, the soldiers run in to see what happened
The king pretends nothing happened and is singing while looking at a musical sheet
He shoos the soldiers away
The stamp is now stuck to his back
so as he comes down from the desk, the desk is toppled
And that causes everything on it to fall down
Scenes like this are a lot of work for those who do the rigging and key animations
Well, director's orders, I guess
So, Cut 11 would require a lot of rigging and animation
And now
The king should be able to move while that stamp is still stuck to him
He has to be flattened by the desk
and then move around a lot
in an effort to get the stamp out
Then he runs outside
But the stamp will still not give
The pain is killing him, but he still pretends nothing happened
And passes by the soldiers
The time has changed from day to night and the Skull King still couldn't get the stamp out
His loyal soldiers bring him his paperwork
which would require him to use the stamp
The soldier leaves the paperwork here
and notices something is off, but his king orders him to leave
Now the remaining motions
are the Skull King on his desk
having no choice but to stamp the papers with his butt
So what we have to create here
is the objects falling from this desk
And the desk having a hole punched in it
You would also have to create this musical sheet
and also the background outside
Of course there would already be some basic assets so you would just have to tweak them a bit
But you do have to keep in your mind what you need to animate
And this stack of paperwork that the soldier brings should probably wobble a bit
And in the end there are these stamped documents that sway as they fall down
So now let's take a look at the assets First is the background
Before we look at the assets required for this specific episode
First let's look at the background of the whole series
Then we will see the requirements for the episode
Project Skull King is a very light, short-cycle project
So the techniques used in the models
are not that difficult
As you can see, excluding the skull, which serves as a signal the outside shot consists of very basic models
And the movement path of the model, created jointly by the director and animators
I should turn on the wireframe
Because the background will mostly consist of
the front space here, or the yard here
A lot of effort went into making sure there weren't any visual flaws
as the camera moves through these two open spaces
As for additional explanation on the outside view
Outside the Skull King's yard, or away from this empty space
there is a sharp decrease in the density of wires
The horizon was done with matte painting
If there is any instance where the camera has to move around the horizon
It would be better to just create a new background
If you put all of the backgrounds in the same file
That would make it very data-heavy which is not good for the animators
which is why it's wiser to make everything that's not the center of focus very light
Especially the sky
You can see that it's all texture images
If I zoom out like this
You can see that the sky and horizon are very low polygon
Another thing I want to mention at this point
There are a lot of open source textures these days
But in the long term it really helps to have your own texture library
That image of the sky wasn't found online
I went outside myself on a sunny day
took a photo of the clouds, and touched it up a bit
The horizon I drew myself as well
If you want it to truly become your own work and portfolio you need to put some time in
Now let's go indoors
And one thing you have to be careful when creating interior spaces
You obviously won't be able to do this all the time
but you should design indoor spaces to be
Let me go indoors
So this is the indoor modeling
and you can see all of the furnitures are there
You should try to match the scale, or hookup
of the indoor and outdoor spaces
Because there might be instances where the camera moves
all the way between the two areas in a long take
To prepare for those instances, you should match the scale in advance
Now with the key points from the animatic we saw
Let's take a look at how I did the modeling Creating Production Assets
This is the interior scene that is shown often
And the first thing I had mentioned was the desk
The desk
As the Skull King sits on it
should have a wiggly motion
I did some additional rigging to make that happen
The desk wasn't rigged before
But as I created this episode, I saw that scene
And added wires to the desk that weren't there before
and used lattice to bind a controller to the desk
Of course, it doesn't matter which deformer you use
As long as you can meet the requirements of the animatic
And a hole was punched through the desk after that
so I added a property to the controller that allowed me to switch meshes
So there's 'normal' and 'broken'
And you can switch between those to create the scene just like in the animatic
And that hole has to fit with something
which is the stamp that made it
And so
this stamp object
should be able to fit right into it
Another important rig was the one in Shot 11
Let's see the animatic again Skull King gets up from the desk
which topples the desk and everything on it
More technical tutorials will tell you to process this using rigid bodies or collisions
But this project is a cartoon animation
So you don't know what the director might order later on
Rather than simulating every single instance like this it's more efficient to just use key animation
So I just prefer to manually bind controllers for the animator
Then how many controllers do you need?
You don't know at this stage
if all that paper will be made to flap around But the most important part here is the Skull King
The detail on the falling objects will receive less attention
So by consulting the director
I got confirmation that there won't be any detail like that
and was able to save time
on rigging the objects
According to their feedback, this amount of motion was enough
which is very light movement
Actually, this is a very common rigging style in cartoon type animation
We should take a look at it for a moment
I separated this stack of paper so it's easier to see
This is a lattice, which is a type of deformer
that is very popular So this object is bound with lattice
and the lattice is bound to the joint on this controller
which allows this movement
This makes it much easier than putting skin directly on to the model
And it also makes it easier to make cartoonish curved motions
So that was some very light rigging
that I animated the paper stacks with
And this is the tower of paperwork in the ending scene
It's very tall, but it's rigged the exact same way
So let's hide everything else again
There's lattice bound to it
which allows you to easily rig this complex model
The lattice is bound to the model
And the joints skin the lattice
which greatly reduces the effort required from the asset team preparing it
It also allows the animator to create the key animation more easily
It curves very easily
So this rigging style
fits the cartoon animation style
We don't even have to see the lattice
It allows you to create key animations very freely
This is my favorite type of rigging
You don't need special techniques, you can use it anywhere, and it won't even cause any errors
Now for the more simpler objects I just added a controller that animators usually require
which is the one that lets you change coordinates
Especially, when creating objects like these
I don't freeze the controller but rather leave some offset
For example, Rotate Y is offset by 30 right now
This is so that the animator
can make full use of the object axes
The same for this piece of paperwork, which is at a slight angle
If I freeze the controller, the animator will have a hard time
because the axes would look like this
So I will leave some offset here as well so that the animator can easily move the object
in the direction that they naturally would
A bit of consideration for the animator will be greatly appreciated for sure
Now let's look at the props
Props in a play mean
the objects that interact mostly with the characters
or are a symbol of a character
which is why you should look at it alongside the character
The most important thing in this episode
I am certain
is this stamp
which has to stick to Skull King's butt
Skull King's hands are modeled to be quite big
Due to that, the stamp is this big while in his hand
But the stamp
that gets stuck here
can't be that size
Due to the nature
of this character's design
So for just this episode
I just stuck a smaller stamp here
and added a property to it
so that depending on the scene
it can be shown or hid
From the animator's perspective adding features like this for them
lets them feel much better while working
Because they will notice
that the asset creator was being thoughtful
And adding a constraint
To stick a stamp here
is actually
a bigger deal than you might think
Because, if more than one animator
had to stick the stamp in the king's behind
They could scale the stamp differently
Isn't that right?
Which is why in this case
the assets team attaching the prop in advance
can prevent in advance
the animators causing the stamp's size to vary
That's also true
for this duster that the Skull King's soldier
is using in the beginning scene
This duster has a very short appearance
in this episode as well
So I just did some light rigging using lattice
And one thing that is important when creating something like this
Because depending on the character
the animator might have to adjust its size
You should add a controller
that allows you to scale size
But it's better if you adjust the size
to fit the character using it in advance
And it would also help to compare with the animatic
Now if you look at the key animation
completed through this process
it really makes you feel good
Now let's view the complete episode
created using the rendered animation
and with sound added
and that's the end of this lesson
Though I only taught two lessons
you have seen the process
of modeling, rigging
and completing a character
And you have watched an animatic
created in cooperation with the production staff
How the cast of characters, props
and models
have to be used in real projects
So you have seen the big flow of production
It was a very short lesson
But I hope you were able to get something out of it
And that is the end of my lesson
Thank you for watching
1. Spline IK and Twisting Spline IK
Use Create Joints to create 6 ik_joints Use Curve Tools>CV Curve Tool to create 6 NURBS curves
Click Create IK Spline Handle, then deactivate Auto create curve to create one ikHandle Use vertices of curve to create movement
If joints cannot keep up with length of curve, add setting to increase joint length
Twisting Set start & end point using two locators(Create>Locator)
Object Up: Local axis in same direction as joints form, twisting joints when they are moved
Object Rotation Up: Adjusted using Rotation value, used mainly for animating hips
2. Production Assets Crucial for production asset provider to understand storyboard and animatic
Background Background in trajectory of primary locations should be modeled in detail
Non-important spaces are rendered in low polygons Putting indoor and outdoor backgrounds at same scale is recommended
Production Asset Modeling Desk with hole in it: Used Mesh Switch function
Pile of paperwork: Bound with lattice, then bound with controller joint Simple props: Added 3 controllers to adjust location
Props that interact with character: Rig to scale with character's hands