koobas.hobune.stream
Instantiate gameobjects at random points on the screen
Dear fellow programmers
I'm very now to Unity and I was trying to make a boid simulation like Sebastian Lague did (His video). I started with a 2D screen and I want to instantiate 10 boids at random points on the screen.
Here is the code I tried. Located in void Start():
for (int i=0; i<11; i++) {
Instantiate(boid);
boid.transform.position = new Vector2(Random.Range(1, Screen.width), Random.Range(1, Screen.height));
}
I quickly realised that this is not going to work tho.
The (0, 0) point is at the center of the screen
I can't just take screen coordinates and convert them into world coordinates
I tried to put my vector2 in Camera.main.WorldToScreenPoint(). But it didn't work. It even put the object further away from the screen.
I did some extensive research over a few days. But I didn't find anything helpful.
I somehow excpected there is an easyer way to convert screen pixels to world coordinated. Like there is a multiplication factor or something.
Anyway I hope I was clear. If you have any more questions feel free to ask and thanks for your help in advance.
You use Camera.main.WorldToScreenPoint(), that would give you the opposite of what you want (world point to a point in pixel space), what you want is Camera.main.ScreenToWorldPoint() :D The point (0,0) then is at the bottom left of the screen, as you can read in the documentation (link below)
https://docs.unity3d.com/ScriptReference/Camera.ScreenToWorldPoint.html
Ok so thats working. Thanks so much. But there is still a little bit of a weird problem. All the boids had a z value of -10. So the were not visible in the game view. I checked that the prefab value was set to 0 and it was. I applied a little bit of a crude fix and manually set all the boids z value to 0 in the code. But do you have any idea what could cause the boids to be instantiated at -10?
That's probably because the camera has a Z position of -10, so when you tell it to transform the 2D position into 3D world space, it just takes that value as the Z component of the vector. So setting it to 0 afterwards is just the right way to do it. :D
Ok thank you so much for your help :)
