Fly uses cubic interpolation to smoothly traverse a series of positions previously named and saved with savepos. The command reset can also interpolate between positions, but it only considers a pair of positions (start and end) at a time, whereas fly can consider multiple positions and generate a path that visits and leaves intermediate positions without discontinuities in motion. See the video mini-example. See also: play, scene, movie-related commands
A position includes model transformations, scale, and clipping plane positions (see savepos for further details). Saved positions are included in saved Chimera sessions.
Fly starts abruptly at the first position, pos1, then proceeds through the list of subsequent positions. Besides positions previously saved with savepos, the current position can be indicated with the name start. (Using the name start in the fly command also saves the position; it could be restored later with reset.) The master-frames argument (default 1) is how many frames each "leg" of the journey (from one position to the next) should take, unless overridden by a frames argument specific to that leg. Examples:
fly 20 start p1- go from the current position to p1 in 20 frames
fly p1 p2 p3- go from p1 to p2 in 1 frame and then to p3 in 1 frame
fly 50 p1 p2 p3- go from p1 to p2 in 50 frames and then to p3 in 50 frames
fly p1 10 p2 25 p3- go from p1 to p2 in 10 frames and then to p3 in 25 frames
fly 40 p1 100 p2 p3- go from p1 to p2 in 100 frames and then to p3 in 40 frames