Beginner's Guide to Rigging in Maya Pt 2 (Notes)

Okay. Heyhihello!! I'm just gonna pick up where I left off last night. 'Bout that time, eh chaps? ...right-o.

This next bit is about joints. Now I already mentioned a bit about joints in last night's post, so forgive me if I repeat myself a bit. 

To put in a joint, you have to be in the 'Animation' option of the drop down menu in the upper left hand corner of Maya. Then from the top bar, choose 'Skeleton' then the 'Joint Tool'. 

It's not a good idea to draw joints in the perspective view. You won't like the results and then chaos will ensue. As we create joints, it automatically creates a hierarchy for us. Two joints parented together creates a bone in-between. Instead of drawing joints in the perspective view, try using the top view. I think you'll get slightly less frustrated at everything mechanical that way. 

After Delano spent a lot of time telling me all the different ways to do this, it only took me like five seconds to create the joints at the shoulder, elbow, wrist, and middle fingertip of this bionic arm. 

By default, the arm rig is not placed within the arm, but on the base of the grid. To fix this, select the root joint (shoulder joint) and hit the Move hotkey, moving that little pest on up into the arm model. If you, like Delano, get really paranoid because you can't see the joints for the model, click Shading and then select X-Ray Joints from the drop down menu. 

After that's all said and done, you want to use the parenting tool that I mentioned in my last post and parent the hand to the hand bone, forearm to the forearm bone, upper arm to the upper arm bone...rather simple, really. 

Keep in mind that maintaining an organized and clean outline (Window > Outline) will make this project so much easier. Rename things so you know what you've got. 

To understand Inverse Kinematics (IK), we first need to understand what Forward Kinematics (FK) is. 

Basically, FK is just the movement of the bionic arm bending at the elbow. IK is going to work the same way because it deals with the rotation of the bones, but so that we'll get an inverse motion. 

Go to Animation > Skeleton > IK Handle tool. 'RP' stands for Rotate Plane and choosing this allows us to get elbow functionality. To create an IK Handle on an arm, go from upper arm to wrist while a leg would go from thigh to ankle. 

And it turns purple. That's cute.

Things can kind of get confusing at this point. Delano was able to do IK Handles with just a couple of clicks. It took me a couple of minutes to get it. But I think I got it the way he wants it...so....

Switching over to the Move tool, select the wrist's IK Handle and move it around. The arm then moves around with it, as it would on a human.

Delano makes the point that if the character needs to plant his hand on something but the character's upper body is still moving around - that hand needs to stay still. IK allows this to be possible. FK doesn't. 

FK is great for walk cycles. 

-evil grin- That's all two videos, less than fifteen minutes of film time. And look at all the notes I give. Look at them, Anikin. Look. :3 Okay, only four more videos to go. This next one is the longest out of the remaining four.

A control object is essentially an object that controls another, mainly for animation. NURBS curves are used quite often for controls because they're non-renderable. Make sure that the control object is going to be easy to select for the animator. Okay, now we have to snap it over to the wrist geometry. Easy way to do this is Show > hide polygons. Holding down the 'V' key makes things snappy. :3 

To clean up this control, we have to make sure that all the values in the translation are zero. To do this without moving the control object, select the object then select Modify > Freeze Transformations. Now all the attributes are nice and clean, which is good and panic-less. But our input isn't clean. Or nice. It's rather rude, really. It's good to clean up the inputs so that animation errors can be avoided. To do this, select Edit > Delete By Type > History. It's a wonderful thing and will probably make your machine run harder, better, faster, stronger. 

Instead of using parenting to get the control object to actually control something, we'll use this thing called constraint. Select the parent then the child (which is the opposite of parenting where you select the child first and then the parent object), then hit 'Shift' while selecting the wrist IK Handle. Then under the Animation menu, select constraint. Ta-da! Pretty. 

Now to move away from this lovely bionic arm and on to a slightly freaky blue alien arm, the next thing is a process called skinning. Sounds absolutely terrifying. But in Maya, skinning is another form of parenting, but on the component level. If you're on a Windows keyboard, then 'F8' will get you to component mode. Otherwise...I'm not sure what the Mac 'F8' is capable of other than playing/pausing iTunes... Sorry about that. Once in component mode (Macs hold down 'fn' and hit 'F8'), we see little purple dot things. These are vertices. They can either be your best friend, or your mortal enemy. These vertices control what happens to the actual mesh of the model, changing the shape, deforming it, etc. 

With skinning, it's the same thing, basically. But the movement is going to be controlled by joints, or what is called influence objects. Skinning is, essentially, parenting these vertices to the bones or whatever influence objects we have influencing the mesh. 

Through a series of things that definitely didn't work and recruiting Stephanie's help, we finally have bending at the elbow. Stupid skinning. Why you no work like Delano said?

What you were supposed to do was select the arm mesh, then Shift select the first two arm joints, which I couldn't do. I have no idea why. Anyways, then you were supposed to go to Skin > Bind Skin > Smooth Skin, but Stephanie did it some other way and it worked. That's my story and I'm sticking to it. 

Now that I have a vague understanding of skinning, I get to learn about editing skin deformations. Select the mesh that has been deformed, then Skin > Edit Smooth Skin > Paint Skin Weights tool. 

Well I've reached the end of my classtime and I do not want to get mauled by little freshmen...so I'm gonna stop here. I've got less than ten minutes of film time left so I'm gonna watch that on my own time but I won't be putting anything about it on here. The next post will be little videos of the things I've accomplished in this lesson.