Go back to the Right Hand Control object window.  Select Bones mode again.  Click 'A' and click-and-drag near where you would expect the tip of the thumb to be.



Go to a Top view, and move the resulting bone forward so that it would be in about the correct position.  You can compare values in the Properties dialog if you want to be extremely exact.

This bone will be named something pithy like "Bone 1". Rename it "Thumb Target".

Go back to the Action window.  You should see the new bone.  Click in the PWS on the DojoBot model, to bring up its skeleton.  Click on the bone for the very tip of the right thumb.  This should create a channel under the Action in the PWS. Right-click this channel, and you will be presented with the opportunity to create a new Constraint.

Create a new Kinematic constraint (if you're wondering why a Kinematic constraint, rather than an Aim-At, click here for a brief digression).  In the properties dialog, click the Object drop-down and select Right Hand Control.  Click the Bone drop-down and select Thumb Target.  The tip of the thumb should adhere itself to the base of your Target bone (although, depending on how exactly you positioned the Thumb target, the change may not be great).

Unfortunately, this Kinematic constraint will be created below the Spherical constraint in the PWS.  If that remaied the case, the kinematics would override the spherical constraints on the thumb, and might cause some kinking.  Click on the Spherical constraint and drag it down in the PWS until it highlights a line beneath the Kinematic constraint.  Drop the constraint, and the two should be reordered properly.

Also, you may find (depending on your finger setup) that it helps the movement of the thumb to loosen up some of the Spherical constraints (particularly giving them some longitude ranges).  Although the Kinematics engine will seldom cause the joints to move into the wider longitude ranges, the "slack" apparently allows it to come to a more reasonable solution of motion.

Take this opportunity to move the Target bone around a little and see how the thumb responds.  Then, when you're ready to deal with the rest of the hand, move on to the next page.



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