The motivation for developing this module came from a desire to produce aircraft-like behavior for a particular fly-by sequence. That is, we wished to produce smoothly banked turns, dives and climbs. Although the Animator module has proven to be a powerful tool for generating a variety of animation sequences, our best attempts always produced jerky motion. Thus we found that we required more precise camera control than that provided by the Animator. The result was a simple splining application which accepted position, view-plane normal, and view up coordinates and generated cubic interpolating splines to provide smooth transition between the data.
The first incarnation of the splining application worked so well it was decided to make the implementation into a module with a similar interface to that of the Animator. That is, the user has the ability to set keyframes and observe the resulting output by hitting a ``play'' button. Similarly, the user may view a particular part of a sequence by selecting the appropriate frame range and again hitting play. Thus users already familiar with the keyframe paradigm of script creation will easily manipulate the Spline Animator. In addition, several special functions which have proven useful in creating animations are included in the Spline Animator module.