Real-time 3D Character Animation with Visual C++

9	Inverse kinematics

For many real-time applications the actions of the characters will be created before the application is run and the interactive game code will select the most suitable action for a particular stage of the game. This provides an effective game style, but what happens when a character needs to reach further than the stored action in order to pick up an item? It would be good if the final position of the character's hand could be determined just by providing a world location for the hand and letting the code determine the orientations of the hand, forearm, bicep, shoulder, torso and hips, that are needed to achieve this goal. Inverse Kinematics (IK) provide this solution and can be a useful addition to any game code engine. ...