Creating A Basic IK System

Once you have learned to create a simple IK rig, the rest of the rigging tutorials you'll read on my site and other sites will be easier to understand. This tutorial won't go through all the details of the IK system. This is just an over-view tutorial.

Set-up

Step one - Download the scene robotleg.mb

Step two - Create a locator (create>locator) and move it so it's sitting just outside the knee. This locator will control the knee.

Step three - Now you're going to create a NURBS circle (create>NURBS primitives>circle). Leave it at the ground level because this will be our foot controller.

Step four - Set your menu set and your shelf to animation.

Create an IK handle.

To create an IK rig, first you have to have a joint chain that's connected to an IK handle.

step one - On the animation shelf, click the IK handle to open the IK tool. Or go to skeleton>IK handle tool.

step two - First we're going to have to define our root joint, or topmost joint (and by define I mean click on the hip joint).

Step three - Now we're going to define the end effector (the last joint you want to be controlled by the IK handle). Click on the last joint.

Step four - Now that we've created a handle, we'll want to parent it to our nurb circle. The nurb circle will control the foot movement. Select the IK handle if it's not already selected and then hold the shift key on your keyboard and select the nurb circle, then go to edit>parent. This will make the IK handle move with the nurb circle.

Step five - De-select everything. Now we're going to make our locator, that we created, control the knee. Select the locator, hold the shift key and select the IK handle and go to constrain>pole vector.

Using The IK Handle

Let's test out our rig. Select the nurb circle and move it up and down. The leg will naturally bend. This is because of the IK handle. Now select the locator and move it side to side. Notice how it controls where the knee is. As you can see this is very useful for posing or animating a character. This is a basic tutorial on creating an IK rig.