Hey there peeps. This is my second tutorial. Yay...anyways lets get to it shall we. This tutorial will focus on creating a foot setup with a foot controller and a footRoll attribute that will be done using set driven key. I must stress the fact that this is not the only way to do it, there are many other ways to do a foot setup, this is just my personal way of doing it. Without further or do, let us begin.
1. Creating the leg and foot
Whenever I create a skeleton I always make sure that the orientation is set to none. That way you won't have any problems with the rotation axes. So with that in mind lets create the leg. You create joints in maya by going to Skeleton > Joint tool, which is found in the animation module.I then went into the Joint tool option box and set the orientation to none. I created the basic leg with three joints for the leg and another three for the foot. I named these joints accordingly, Hip, Knee, Ankle, Heel, Ball and Toe. Below is a pic of what it looks like. If you do want to change the position of your joints, you should do so by selecting the joint you want to move and hitting the Insert key and then changing it's position. That way you won't affect the other joints in the process.
2. Preferred angle and IK Handles
We will now set the preferred angle of rotation for the knee and create all the IK handles for the leg and foot. Firstly lets set the preferred angle for the knee. Select your knee joint and rotate it in the X axis about 30degrees or so (the value is not that important really, as long as it rotates in that direction). Once it has been rotated, right click on the knee joint and select "Set Preferred Angle". Once that is done, just set the Rotate X value (In the channel box) of the knee back to 0, so that the knee goes back to it's original position. Reason we did that is, when we assign the IK handle, we want the IK handle to bend the knee in the right direction. So now that we have set the preferred angle, the knee will now bend in the right direction. Hope that makes sense to you.
Now lets create all those IK Handles. You create an IK handle by going to, Skeleton > IK Handle Tool. Go into the IK Handle option box and make sure that the current solver is set to the IK Rotate Plane Solver (ikRPsolver), and make sure sticky is un ticked. Leave everything else at it's default settings. Cool, once all that has been done, create the IK handle from the Hip Joint to the Ankle Joint (in that order), by simply dragging a selection box around the hip joint and then dragging again around the ankle joint. Now the IK handle has been created. Name the IK Handle "KneeIK". Now if you move that IK handle up, you will see that the knee bends.
Cool, now create another IK Handle from the Ankle joint to the Ball joint (in that order) and name that IK Handle "AnkleIK", and then create another IK Handle from the Ball Joint to the Toe joint (in that order) and name it "ToeIK". So now you should have a total of three IK handles.