Games

How to rig a face for animation

How to rig a face for animation

Once I was first studying to create character rigs in Maya means again in 2002 whereas engaged on the Ps 2 title Superman: Shadow of Apokolips, the rigs we used weren’t most effective, and Set Pushed Keys (SDKs) have been used for almost the whole lot. 

The arms have been pushed by them and so have been the facial expressions, in reality almost each management had some kind of SDK concerned. Do not get me mistaken, the Set Pushed Secret is a highly effective device in Maya, however you may need to plough via a load of Maya tutorials to determine it out. It may be time-consuming to arrange, and is straightforward to break and a ache to repair. Plus, your scene measurement can find yourself bloated by animation curve knowledge.

Over the previous few years I’ve been experimenting with one other strategy in Maya, however this time for extra high-end rigs as opposed to recreation ones. One which is extra environment friendly and usually simpler and far faster to implement into a rig. The method ought to provide the fundamentals of rig creation. 

On this tutorial, I shall be taking you thru the steps of rigging a character’s face, however relatively than specializing in the extra primary areas like joint placement and weight portray, we shall be taking a look at an typically ignored facet of Maya… the utility nodes.

The phrase nodes can appear to be an intimidating one and be related to extremely difficult rigs involving locators, splines and different complicated techniques, however don’t be concerned. With this setup you may be utilizing a mixture of blendShapes, joints and nodes to make a extremely versatile character able to a wide selection of feelings. 

After you have adopted this course of you possibly can then adapt this rig for one other character, including extra controls to simplify animation and make it simpler to create 3D artwork. There’s additionally a video to accompany this tutorial.

Discover all of the belongings you will want right here.

01. Create mesh topology

3d model of man with mesh

Be sure your edge loops comply with muscle strains

Earlier than you begin to construct your rig, you want to do some investigation work. The mannequin you’re rigging and its topology are important to how nicely the character will transfer, particularly if, like on this occasion, you’re specializing in the face. It is necessary that the topology just isn’t solely clear however that the sting loops comply with pure muscle strains. In the event that they do the face will deform in a far more practical method.

02. Make basis shapes

models of man's faces, with and without eyes

Create your first batch of blendShapes

As soon as you’re proud of the topology it is time to begin creating your first batch of blendShapes and doing this now may also spotlight any hassle areas with the mesh early on. These blendShapes are full facial poses overlaying all the primary expressions wanted, however sectioned into key areas just like the mouth and eyes. We’re wanting for the elemental shapes right here like a smile, frown and so forth, in addition to the higher and decrease eyelids absolutely closed.

03. Add extra shapes

3d model of man's head

Keep in mind to add blendShapes for each vast and slender mouths

With this rig you’re going to depend on eight primary controls to manipulate the lips so it is essential to additionally add blendShapes for a broad mouth in addition to a slender one which might additionally double because the pucker. That is so manipulating a single management can primarily pull across the nook of the mouth to obtain a extensive variety of expressions and transfer between all 4 blendShapes directly.

04. Cut up the blendShapes

man's 3d head

Cut up your shapes into left and proper sides

With the primary shapes created, it is time to transfer to part two. What you want to do subsequent is cut up them into left and proper sides which means you possibly can pose them independently. A fast means to do that is to create a blendShape node after which edit its weights, as illustrated within the field on the left. This can restrict its affect to only one aspect of the mannequin which means you possibly can then duplicate it and hold this copy to create your particular aspect.

05. Construct the skeleton

man's 3d head

Subsequent up, construct your skeleton

The subsequent stage within the facial rig is to construct your skeleton and as talked about earlier, for this setup we’re going to be utilizing each joints and blendShapes to pose the characters options. I like to use blendShapes as they may give you extra exact shapes, however then the joints may help to push and pull areas of the face round to offer you extra flexibility.

06. Controls or a UI?

man's head model in Maya

Whether or not you employ controls or a separate UI is up to you

Whether or not you create controls which float in entrance of the character’s face or use a separate consumer interface is up to you, or extra possible up to the animators who will probably be utilizing your rig. Now it is time to begin creating these controls and for this tutorial we can be utilizing a mixture of the 2. A principal UI can be used to management nearly all of the blendShapes, however a collection of controls may even assist to manipulate the rig in locations the place it wants to transfer in all three axes. 

07. Use direct connections

man's face model with distorted mouth

Keep away from scenes like this through the use of direct connections

When utilizing a separate UI as we’re, you could have to strategy the rig in another way. Historically you possibly can use Constraints to tie a particular joint to its grasp management and in flip this management would naturally comply with the top. With a UI, the controls are static and do not comply with the top so utilizing Constraints will lock the joints to the controls which means should you transfer the top the joints keep the place they’re. A means round that is to use direct connections as an alternative of constraints.

08. Driver locators

direct connections in Maya

Direct connections have their very own points you will want to work round

However utilizing direct connections by way of the Connection Editor will pressure the translations, rotations and scale attributes to match these of the controls. Your joints inherently have translation values utilized which can find yourself modified when related. You possibly can work on an offset system or you might create a locator within the place of every joint, freeze its transforms after which Father or mother Constraint the joint to the locator. So the locator, now with zero attributes, will drive the joint.

09. Join the locators

connect locator in Maya

Use the Connection Editor to hook up controls to the locators

With the locators now in place and the joints dad or mum constrained to them, you possibly can join the controls from the UI’s attributes to the locators utilizing the Connection Editor. If the locators are additionally parented to the top management they’ll comply with its motion no matter the place the UI controls are. Additionally, the joints will now transfer relative to the top’s place and never be locked to the UI which means you can even place the UI anyplace within the scene.

10. The situation node

the condition node Maya

A situation node, yesterday

It is time to begin connecting the blendShapes and introduce the primary utility node, which would be the Situation node. That is my favorite utility node and what it does is take a worth, just like the Y translation of a management and, if it goes over or beneath a particular worth it outputs one other worth. For instance, if the management goes over Zero within the Y translation then we will set off the smile blendShape, if not, it’s ignored. So let’s set this up.

11. Deliver every thing in

node editor in Maya

Simply deliver all of it into the node editor

Open the Node Editor and choose the Lip_Left_Outer_Control, clicking the Add Chosen Nodes to Graph button to deliver it in. Now press Tab within the Node Editor and begin typing Situation within the small window and choose it from the menu under to create it. Lastly choose the primary blendShape node on the character’s head mannequin, referred to as Head_BShapes, and comply with step one once more to deliver it into the Node Editor.

12. Join the node

nodes in Maya

That is the place it begins to get a bit difficult; hold in there!

Now join the Lip_Left_Outer_Control.translateY attribute to the First Time period attribute within the Situation node. 

Depart the Second Time period as Zero and alter Operation to Larger Than. 

Subsequent join Lip_Left_Outer_Control.translateY to the ColorIfTrueR. (This implies when the First Time period is Larger Than the Second Time period it should use the true worth.) 

Join the OutColorR attribute to the Left Smile blendShape attribute and transfer the management to see what occurs.

13. MultiplyDivide node

nodes in Maya

Decelerate the smile blendShape’s motion a bit

The smile blendShape is now triggered solely when the management is moved within the Y axis, however it might be influencing it an excessive amount of. You need to use a multiplyDivide node to scale back its affect and decelerate the motion. Within the Node Editor press Tab and create a multiplyDivide Node. 

Join the Lip_Left_Outer_Control.translateY attribute to the input1Y attribute within the multiplyDivide node and its OutputY attribute to the ColorIfTrueR attribute on the Situation Node.

14. Modify values

node editor

Change the Input2X attribute to alter how a lot stuff strikes

Whenever you transfer the Lip_Left_Outer_Control, the smile will look no totally different, that’s till you modify the Input2X attribute within the multiplyDivide node, which is the quantity the Input1X worth is being divided by. Altering this to Zero.5 will halve the quantity the blendshape strikes as a result of it is halving the Y translation worth. Equally, a worth of -Zero.5 will reverse it and half it, which is essential to keep in mind if you join future controls. 

15. Join extra controls

node editor Maya

Use the identical course of to set off the extensive mouth blendshapes

That is simply the smile blendShape added, however now you can comply with the identical course of to make the X translation of the management set off the broad mouth blendShapes. With the other instructions, so a minus X and Y motion, set off the pucker and frown shapes, ensuring you additionally change the Operation within the Situation node to Much less Than. This can make sure that these blendShapes are triggered solely when the worth drops under Zero somewhat than above.

16. UnitConversion node

node editors

Use a easy direct connection for jaw motion

You do not all the time have to create a new node to edit the affect a management has over one thing. With the jaw motion, quite than use a utility node you should use a easy, direct connection to make the translations of the management impact the jaw joints’ rotations. When related Maya will mechanically create a unitConversion node by default between the connections which you should use to your benefit.

17. Sluggish the jaw

node editor Maya

Edit the Conversion Issue attribute to sluggish the jaw down

Should you discover your jaw is rotating too shortly you possibly can then edit the Conversion Issue attribute discovered within the unitConversion node, relatively than introducing one other multiplyDivide node to sluggish it down.

18. BlendColors node

maya nodes

Use the blendColors node to mix between two different values or controls

With simply these few nodes you’ll be able to see how a lot we now have achieved and from right here you possibly can fortunately work your method across the face and join up the remaining controls. We will, nevertheless, do extra with the assistance of the blendColors node. Regardless that this will work together with your typical RGB values, you may as well utilise this node to mix between two different values or controls, making switching and mixing simpler.

19. Make sticky lips

face in Maya with lips stuck together/not

Make lips stick along with the blendColors node

An necessary a part of any mouth rig is for it to have the power for the lips to stick collectively, no matter the place the jaw is. Think about the character wants to chew one thing, regardless that the jaw is shifting the lips want to stay sealed. To assist obtain this you should use the blendColors node to dictate whether or not the decrease lip driver locators comply with the jaw or the higher lip management.

20. Lip teams

node editor Maya

Divide the lip management locators into three teams

First you want to divide the lip management locators into three teams. Upper_Lip, Lower_Lip and Corner_Lip and ensure their pivots are in the identical place because the jaw joint. That is in order that they rotate across the similar level. Subsequent convey the StickyLips_Control, Lips_Control, Lower_Lip group and in addition the Jaw driver locator into the Node Editor and create a new blendColors node. 

21. Join the lips

node editor maya

Hook all this stuff up to a bunch of different issues

Join the Lips_Control.rotate attribute to the blendColors.color1 attribute. Repeat with the jaw locator connecting its rotations to the blendColors.color2 attribute. 

Join the blendColors.output into the Lower_Lip group’s rotation attribute. When you manipulate the Blender attribute on the blendColors node the decrease lips will mix between the 2 values. 

Join the StickyLips_Control’s Y translation into the Blender attribute so the management drives it.

node editor Maya

You might want to create a midway level blendshape for when eyes are partially closed

As an additional tip chances are you’ll discover that due to the linear nature of blendShapes, the eyelids transfer by means of the eyes when activated slightly than over them. On this occasion you might want to create a midway level blendShape for when the eyes are partially closed. This will then be added as an in-between goal in your blendShape node, which is then triggered up to a specified level earlier than the primary form takes over.

23. Honorable point out

node editor in Maya

Shout out to the Reverse and plusMinusAverage nodes

I could not finish the tutorial with out mentioning a couple of different useful utility nodes which have helped me through the years. These are the Reverse and plusMinusAverage nodes. The names are fairly self explanatory with the Reverse node successfully inverting a given worth, the plusMinusAverage node is analogous to the multiplyDivide node, besides it permits you to carry out totally different mathematical equations.

24. Time to experiment

face in Maya

Now go forward and mess around with all of it

If you need to see extra of this rig, obtain the accompanying video and related information, and be happy to take a take a look at how the remainder of the character has been arrange. 

This text initially appeared in 3D World journal, the world’s greatest promoting journal for CG artists. Subscribe right here.

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