Moving AI

Scripting
1

So I’m working on a fly AI, I started by creating basic functions for things like moveRight(), moveLeft(), moveUp(), moveDown(). These are incredibly useful and functional movements, but the only thing I dont get out of these is a rounded movement. They are all straight lines, combined functions like my diagMoveRightUp() which is simply moveRight(); moveUp(); work fantastically for a diagonal line. So using transform.position methods what would be a good way to make a curve style movement or archs?

Edit: This is a 2D game just fyi.

2

In kinematic motion, archs and curves are usually the result of acceleration being applied to some velocity. Eg: An object sailing through the air is accelerated by gravity, which causes it’s path to look like a quadratic function.

This example shows an object that is moving up and to the right, before gravity pulls it back down in a quadratic arc.

void Start() {
  // This would be 50 meters per second to the right,
  // 100 meters per second upwards.
  velocity = new Vector2(50, 100);
}

void Update() {
  // Apply gravity to velocity
  velocity += Physics.gravity * Time.deltaTime;
  // Move the object according to it's velocity
  transform.position += velocity * Time.deltaTime;
}

Vector2 velocity;

EDIT: If you can somehow restrict the way the player can move every time, you may be able to set up a limited number of curves in advance. If you want freedom of movement calculated through code, there’s gonna be a bit of math and physics involved in getting your curves!

3

It sounds like you might be working on a SHMUP. If you are, then I might do something like this.

/// Maximum left-right and up-down speed.
float speed { get; set; }

void Update() {
  Vector2 velocity;
  velocity.x = Input.GetAxis("Horizontal");
  velocity.y = Input.GetAxis("Vertical");
  velocity *= speed;
  transform.position += velocity * Time.deltaTime;
}

EDIT: Ah so I’m reading this post again and I realize it’s for AI. Instead of using Input.GetAxis(), you can come up with your own Vector2 velocity value any way you want. (The easiest two I can think of are fly towards the player, and fly away from the player.)

4

This is perfect. A great start! Thank you Garth, it’s very much appreciated.