Implement the ability to choose various animation playback types such as "loop" or "boomerang". This would be implemented in the handle_animation function.

This is a very simple feature to implement (development time <1 hour).

Hi there,

The 0 BUFEXCHG meta command originates from the MLCAD program but is also supported in a range of other LDraw programs such as LDCad, LPub3D and LeoCAD. The command can be used to "remove" parts during the building process. The typical use case is to show a certain part hovering above the model in one step, and then in it's final position in the next step. This can be tremendously u