Terry Brunt - Computer Animation Arts: Maya Tutorials

We went through three different rigging tutorials this time, so I can't think of a fitting title.

Anyway, as is the norm, lesson started with a 5 minute Moom posing challenge.

Comparing the Moom I posed to the reference, you can see what I've missed out on.

Moom is too rigid, where as the ref's spine is slightly tilted to the side.

I never got around to posing the hands.

I forgot to pose the feet and the knees are a bit too bent, resulting in Moom looking like they've just landed from a jump, rather than going into a jump, like the reference.

At least Moom isn't injured this time.

On to the actual lesson.

Task 1: Curve Driven Squash & Stretch

Starting with the familiar torso of Jetpack Jones.

When rigging JPJ you make a ribbon spine, in this ribbon spine is a specific curve. This curve is used to create a custom node, a curve info node, used to make squash and stretch work with the model. To create this node type "arclen -ch on ribbon_volume_driver_crv" into the MEL command line. Once executed, bring the curve into the node editor.

Here is the node editor with the ribbon curve fully graphed out.

Going back to the ribbon spine, select the three control joints and bring them into the node editor.

Here is everything laid out so far.

Just like the tutorials from last week, three multiply/divide nodes are needed to get this to work. One normaliser, then one for the square root, and then a last one to divide. In the actual lesson, Alan did show us how to change each joint individually, however I can't remember how he did this, so I'm not going to have a very good squash.

But here we have Stretch Pack Jones.

Task 2: No Flip Pole Vector

Back to the half rig from last week, we look at the leg this time.

The leg rig has a separate control for the knee, which is gives more control for animating, but it can be a bit of a pain when trying to do something simple, like walking.

Delete the knee control and set all the pole vector values to 0.

Bring out the pole vector's X value. Also add a "Twist Ctrl" attribute to the foot control.

Bring the leg IK and the foot control into the node editor, as well as adding a plus/minus/average node.

Plug the foot control's Twist Ctrl into PMA input 1D[0]. Plug the leg IK's Offset into input 1D[1]. Then take output 1D and plug it into the IK's Twist. Make sure to set the IK's offset to 90 at this stage.

If it all worked, you should now be able to control the knee from the foot control.

Task 3: IK/FK Switch

Starting with this half a torso.

Duplicate from the shoulder joint twice.

Delete the fingers from the duplicates, as we'll only need the shoulder, elbow & wrist joints. Rename each chain (Bind, IK & FK). Individually parent each IK/FK shoulder & elbow to their Bind counterparts. Connect the wrists with point and orient constraints.

Create a locator and place it above the shoulder. Add attribute: L_Arm_IK_FK. This is the switch. Using set driven keys, connect the locator to the IK and FK constraints.