The view that only the entry and exit points matter is the one I have understood for all my Traveller time, as well as anyone I have ever met who discussed the physics, including those who wrote about it. However, in a discussion elsewhere on this board, the case is made that this does not hold true for the rest of the universe.
Thrash found out that there were two views, and pegged MWM on whether jumpspace has 1-to-1 relationship with n-space and MWM said it does. (Rather, he IMPLIED it does, if we're going to make such distinctions.) And that is why jump-masking came to be the official truth in GURPS Traveller. This led to a rather large discussion between the denizens of this board, one side taking things literally and one side taking them metaphorically, and neither side really willing to give up.
The fact of the matter is, GT's representation (clarification?) is now the "official" representation. Jumps are straight lines. Intervening objects are disasters. New military tactics are possible to defeat enemy invasion fleets, with nary a shot needing to be fired. Piracy gains a whole new life too. Ship designs REQUIRE 2 jump minimums to avoid some of the new tactics, but not all can be avoided so simply. The face of the universe has become unrecognizable due to this one little change.
But at least now there's more details to consider!
The Earth travels at about 30 km/s around the sun. Mercury, which is at about 1/3 the distance, is only about 50% faster, at about 45 km/s. A world whipping around a M8 star in its hab zone will probably be considerably faster, but I haven't calculated that out.
30 km/s is about 1 hour of thrust at 1 Gee. This means that if you are jumping between two worlds that are like Earth, but going in opposite directions, then you need to apply 2 G-hours of thrust to make up the difference. This is probably prefered for the outbound jump. There has never been any mention that your velocity affects jump, though I would believe near-c velocities matter if some one said so.
You want to have 0 velocity relative to the world you are coming to, or perhaps some velocity toward it. In either case, I think you want to aim for the tail end of it's path, where it "just was", so you don't bump into it.
Worlds really close to their star, which whip around their world in like 2 weeks, well, they're deep within the jump shadow anyway, so you're going to want something of a high velocity when you come out. You're going to need to know where the world is, so you can intercept it when you want to. You'll want your vector aimed so that you come in from behind it, so that it's not going to plow into you if you lose power suddenly.
Finally, any world is going to have a traffic net. Simply stompiong on the gas and saying you'll be there in an hour is going to be quite silly on a heavily trafficked world. Traffic control will ban you if you come in at the wrong time. Outgoing control tells you before you leave what the proper approach vector for your destination is. When you get there, they expect you to be on the right vector, though the vagarities of jump time are going to mess this up some.
Still, it is best if you assume jump USUALLY lasts 150 hours (or whatever it was), and that only non-optimal jumps will take more or less time. Getting there too soon CAN be a disaster, if the world isn't where it needs to be yet. It is also best to assume that jump lands you right where you wanted MOST of the time, unless you did something less than optimal.
As the vector difference between most worlds outside their parent-star's jump shadow is easy to make up with about 2-4 G-hours of thrust, I wouldn't worry too much about it, and say that the ship accelerates all the way out and all the way back in, minus a fudge factor on the inbound leg to cover inaccuracies and traffic control.
Thrash found out that there were two views, and pegged MWM on whether jumpspace has 1-to-1 relationship with n-space and MWM said it does. (Rather, he IMPLIED it does, if we're going to make such distinctions.) And that is why jump-masking came to be the official truth in GURPS Traveller. This led to a rather large discussion between the denizens of this board, one side taking things literally and one side taking them metaphorically, and neither side really willing to give up.
The fact of the matter is, GT's representation (clarification?) is now the "official" representation. Jumps are straight lines. Intervening objects are disasters. New military tactics are possible to defeat enemy invasion fleets, with nary a shot needing to be fired. Piracy gains a whole new life too. Ship designs REQUIRE 2 jump minimums to avoid some of the new tactics, but not all can be avoided so simply. The face of the universe has become unrecognizable due to this one little change.
But at least now there's more details to consider!
The Earth travels at about 30 km/s around the sun. Mercury, which is at about 1/3 the distance, is only about 50% faster, at about 45 km/s. A world whipping around a M8 star in its hab zone will probably be considerably faster, but I haven't calculated that out.
30 km/s is about 1 hour of thrust at 1 Gee. This means that if you are jumping between two worlds that are like Earth, but going in opposite directions, then you need to apply 2 G-hours of thrust to make up the difference. This is probably prefered for the outbound jump. There has never been any mention that your velocity affects jump, though I would believe near-c velocities matter if some one said so.
You want to have 0 velocity relative to the world you are coming to, or perhaps some velocity toward it. In either case, I think you want to aim for the tail end of it's path, where it "just was", so you don't bump into it.
Worlds really close to their star, which whip around their world in like 2 weeks, well, they're deep within the jump shadow anyway, so you're going to want something of a high velocity when you come out. You're going to need to know where the world is, so you can intercept it when you want to. You'll want your vector aimed so that you come in from behind it, so that it's not going to plow into you if you lose power suddenly.
Finally, any world is going to have a traffic net. Simply stompiong on the gas and saying you'll be there in an hour is going to be quite silly on a heavily trafficked world. Traffic control will ban you if you come in at the wrong time. Outgoing control tells you before you leave what the proper approach vector for your destination is. When you get there, they expect you to be on the right vector, though the vagarities of jump time are going to mess this up some.
Still, it is best if you assume jump USUALLY lasts 150 hours (or whatever it was), and that only non-optimal jumps will take more or less time. Getting there too soon CAN be a disaster, if the world isn't where it needs to be yet. It is also best to assume that jump lands you right where you wanted MOST of the time, unless you did something less than optimal.
As the vector difference between most worlds outside their parent-star's jump shadow is easy to make up with about 2-4 G-hours of thrust, I wouldn't worry too much about it, and say that the ship accelerates all the way out and all the way back in, minus a fudge factor on the inbound leg to cover inaccuracies and traffic control.