Change path in IK example

[iamtesch]

On the basic IK example, it traces a straight line from [0.5, -0.2, 0] to [-0.5, -0.2, 0]. This works OK on the 3 dof arm, but points that are passed through in the vicinity of [0.2, -0.2, 0] tend to be a little collision prone with a 6 DOF arm, given the wrist and the gas spring. I found a trajectory of [0.5, -0.2, 0] to [0.5, 0.2, 0] to work better here, and I think it would work well on the 3 DOF arm as well. It also seems to center better in the default workspace (so an elbow up configuration with base angle "0" is in the middle).

Thoughts?

[daverolli]

The source of this was that this demo doesn't actually run on a real arm. But its pretty reasonable for someone to expect that this would, so I like the change.