# Constant force over terrain / rail track

Hey guys.

I would like to make some game, which would use something like locomotive tracks. That means, i need the track (but it can be even invisible object) and something moving along it.

But whats the problem… if i tried in blueprint just AddForce to pawn on the scene, it works good on flat terrain, but problem is, if the pawn should be moving over raised terrain… then the force is not sucifient to make it moving…

It would need bigger and bigger force to move across the raised terrain.

How to solve it?

Basicly, i would like to have something like motor or engine, on the end of some tunel, which would be pushing the objects before the motor in forward direction.

But:

1. i dont know how to make some motor like that (yes i managed to apply the force, or linear velocity, but of course that needs some location vectors which should be constantly updated on different places of track - but that could be theoretically possible using some helper objects along the track, and using their location as pushing direction)

2. then there is bit problem the tunel or track itself, because it must be curved object, which perfectly fits the terain etc… But may be this object is not needed, in case there is some solution for problem number 1.

For example i can disable gravity on the pawn, then it goes over raised terrain, but once it is on the top, it flies away haha

Another solution, or idea how it should work would be - make some object to be sticky to some curved line on the ground, be able to set some constant velocity on them, while ignoring the gravity force while going up to raised terain, or may be ignore gravity at all, in case the object will be sticky to the line on the ground, and moving constantly.

Lukas

Hi lukas84,

Have you thought about animating a TargetPoint via Matinee and then having the camera/object follow it? This may not be exactly what you are trying to accomplish but you could possibly use some of the techniques for your setup.

I hope it helps.

Hello TJ, thank you i will check it.

It sounds as another type of solution, quite interesting.

As for my origin question, and the part that i dont know how to make pushing motor, i found that Physic thruster could do that, however, it again works somehow strange that means the power is not constant. (and it would need also the second part, the trajectory line / tunel)