Using Interactive IK

Set up:

• Continue from the previous lesson or open tut_mech_03c.max from the \tutorials\mech_design directory.

Use Interactive IK:

1. Be sure your Perspective viewport is active and full screen.

2. On the toolbar, click Select And Rotate.

3. Press H and select LOWER ARM from the list.

   In the next step, you will rotate the LOWER ARM to see the effect. You don’t want the transform to be permanent, so be sure to right-click before you release the mouse button. This will cancel the transform and return the object to its original position. If you inadvertently release the mouse button, click Undo to reverse the operation.

4. Place your cursor over the Y-axis of the LOWER ARM transform gizmo. Click and drag up and down, then right-click to cancel.

   The LOWER ARM rotates up and down, but the rest of the assembly does not move with it.

   In order to have the rest of the assembly follow the LOWER ARM, you have to set the Interactive IK toggle. This causes Autodesk VIZ to recalculate the positions of objects in kinematic chains when a child object is transformed.

5. On the command panel, click the Hierarchy tab.

6. On the Hierarchy panel, click IK.

7. In the Inverse Kinematics rollout, turn on Interactive IK.

8. Rotate the LOWER ARM along the Y axis of the transform gizmo. Right-click to cancel.

   The LOWER ARM rotates, and the rest of the assembly follows as required.

9. On the Hierarchy panel, turn off Interactive IK.

Save your work:

• On the menu bar, choose File > Save As. Name your scene myassy01.max.