- Home /
When should a newtonian spaceship start slowing down?
I'm working on a 2d (top down) spaceship shooter with newtonian physics. I'm having some trouble with the ship AI though.
I want it to begin to slow down when it is nearing it's target, the trouble is, how does it know when to start slowing down? I guess it would be a factor of the mass of the ship (no drag), the velocity and the maximum reverse thrust (applied via rigidbody.AddForce(transform.right (-maxThrust Time.deltaTime));).
Sorry for the maths problem :-)
Well, yes, it is just a pure math problem. Nothing to do with Unity, or really with games.
Correct answer: for a game, do whatever makes it the game "feel" right, and ignore how it really would work. If you want it to "feel" real, just pick a distance from the space station that looks good, and 3-8 seconds of fake slowdown (based on pilot skill, since that's fun.) Consider making it an easy $$anonymous$$i-game.
$$anonymous$$ath answer: It's the same as tossing a ball in the air (tilt your head sideways.) Gravity is like the reverse thrust. That's a known equation. Let H be your stopping distance and solve for G.
I tried making up average slow down distances and they would work fine until you applied it to ships of different mass and thrust.
The answer below worked, now I can just add a random modifier on the distance based on how difficult the current AI should be.
Answer by Kavorka · Apr 04, 2014 at 03:14 PM
I derived the formulas. They are:
distance = velocity^2 / (2 * acceleration) or
distance = velocity^2 mass / (2 thrustForce)
That worked brilliantly!
$$anonymous$$athf.Pow(forwardVelocity,2) * rigidbody.mass / (2 * thrust);
When my ai reaches that distance from its target it now begins to slow down and stops pretty much exactly on target.
Your answer
![](https://koobas.hobune.stream/wayback/20220613141926im_/https://answers.unity.com/themes/thub/images/avi.jpg)
Follow this Question
Related Questions
Calculating the perpendicular direction an AI ship needs to face to fire its cannons? 2 Answers
AI reflect shooting 0 Answers
Advice on my Ship AI... 4 Answers
Determining thruster activation on 3D spaceship 1 Answer
Enemy strafing AI Top Down 0 Answers