DeepSOIC wrote:I thought a bit on a concept of a trajectory of motion of a solid body. That is, Placement vs time. That is, trajectory with orientation. It's a kind of path, or a trajectory, and it must be of great importance in camera motion (animation), simulation, rockets and planes and autopilots, CNC,... I feel like there must be a term for it.
Any ideas?
Hi deepsoic
My understanding is that trajectory means the path that an object travels through and includes time, hence velocity....but does not have anything to do with orientation of the object itself relative to the path.
For example two artillery shells could theoretically be fired such that they travel the same path over the same time, yet with a different spin rate due to a difference in the riffling, they would both be described as having the same trajectory. Yet a bird flying through the exactly the same path but of course much slower, would therefore have a different trajectory because it took the bird longer even though its path was the same.
Or for a less distasteful example, the Apollo moon capsules had to fly through a path that caused them to hit the atmosphere at a very small range of angles so that it did not either bounce off the atmosphere or pull too many Gs and kill the astronauts or burn up, which meant the accuracy of their trajectory (or flight path) was critical. But they also had to control orientation, they actually controlled the orientation by small amounts to steer the capsule or change its trajectory (flight path) once they had hit the atmosphere.
Anyway I digress ....as far as I know in English what you describe requires two words, "trajectory" and "orientation"...but others may know of something I have not thought of.
Jim
