I am currently making a 2d tower defense game with a static, predetermined lane that the enemies follow (i.e. towers cannot block the path and path finding is not the problem I am trying to solve).
I am trying to figure how exactly to make units follow this lane in a smooth way. I have two rough ideas about how to do this, but I would love some input on which is likely to be easier to implement/the more standard technique. Or of course if I there is some totally different way that I haven't considered I would love to learn about that as well.
Waypoints: My first idea was to define the path as a series of hard coded waypoints. Units would then use a basic "seek" steering algorithm (such as this one) to move to each waypoint along the path in succession. However, I have wondered if it might be hard to keep the units from deviating to much from the lane I want them to follow. I wonder if inability to turn sharply enough might cause them to sort of "glide" out off of the desired lane. I suppose I might be able to prevent that though by allowing for a relatively strong steering force to be applied?
Bezier Curves: The second solution I have considered is to define the path with a bezier curve and at each time step calculate the point along the curve with is (dt * speed) away from the unit's current location. I suspect that this technique would make it much easier to precisely define the path that units will follow, but I don't know know how exactly to go about implementing this. Any suggestions?
Also, I don't this will change anyone's answers, but units also must be able to travel at a constant speed along the path. Additionally, I am programming this game in python using the pyglet framework.
If anything about the question is unclear please let me know.
Edit: Also for whatever its worth, I'm sort of trying to replicate the movement behavior of enemies in the Kingdom Rush.