Graphics Programs Reference
In-Depth Information
Figure 9.74
Create an IK handle
to attach the wheel
arm and the back
wheel to the control
wheel.
If you group the IK handle, as shown in Figure 9.75, you'll run into a problem when
you animate. Let's try it: Group the IK handle (ikHandle2) under the end back
wheel, as shown in Figure 9.75, and then rotate the control wheel. The wheel arm
pumps back and forth along with the back wheel, but every now and then the wheel
arm geometry flips over backward. This isn't good.
Fixing this is easy. The grouping of the IK handle to the back wheel is causing the
issue. Although that is pretty much what you want to do, parenting the IK handle
under the wheel is problematic. Here is where the parent constraint becomes
extremely helpful. It gives you the desired result without the geometry flipping.
Figure 9.75
The wheel arm
geometry flips over
if you group the IK
handle under the
back wheel.
