Unity3D-如何独立地在正弦波中移动对象？

Question

In my game I have targets that spawn and move towards the player in a straight line. I use this code:

transform.LookAt(target.transform);
transform.position = Vector3.MoveTowards(transform.position, target.transform.position, speed);

Which makes the target home in on the player and move towards them.

I decided to try and make them move in a sin wave, so it looks less boring than going in a straight line, and I added a line of code, which now becomes:

transform.LookAt(target.transform);
transform.position = Vector3.MoveTowards(transform.position, target.transform.position, speed);
transform.position += transform.right * Mathf.Sin (Time.time * 3f) * 1f;

Now this works great, my enemies move left and right as they travel towards the player, except, they all follow the same path at the same time, resulting in a large group of targets moving left and right in a sort of choreographed way.

I believe it is because I use Time.time in the Mathf.Sin piece of code, which results in all the targets using the same value to generate a sine wave.

I've tried changing to Time.deltaTime and changing the Time.time variable to a Random.Range variable between 2 numbers, but they either don't work, stop my targets from moving, or make them look like they are vibrating. I've also tried using animations as well, but because of my MoveTowards code, this doesn't work either.

So, is there a way to make a GameObject move left and right in a sine wave and move forwards at the same time, but independently so they do not look choreographed? :-)

Answer 1

In order to offset the phase of the sine function (while keeping the frequency and amplitude) you have to add a constant to x in sin(x).

So you could try transform.position += transform.right * Mathf.Sin (Time.time * 3f + i) * 1f; where i is unique to the target moving towards the player.

See also: https://en.wikipedia.org/wiki/Sine_wave