Start rotation Random Number

Unity Engine
1

For the first day of using Unity it is a lot of fun. I am following some tutorials and reading through the docs, lots of doc’s. For a simple project I an dropping a cube on to another cube with collision detection and watching it bounce. The results every time I run it are identical which is expected. I decided to have a random number be generated to allow different results but it seems not to be working.

I assigned a script to the cube that drops. I can see that Debug.log is triggered and the result is random every time but the box seems to drop the same way every time? I am simply adjusting 1 axis.

#pragma strict
var startRotation:float = 45.0;

function Start () {
	startRotation = Random.Range(0.0, 359.0);
	 transform.rotation.x = startRotation;
	 Debug.Log("Fiered"+ startRotation);
         
}

function Update () {

}
2

Transform.rotation is a 4D quaternion…as the docs say, don’t try to modify a quaternion directly unless you understand them inside out. It can still be problematic to modify Transform.eulerAngles, so the best thing is to use Transform.Rotate.

–Eric

3

To set the eulerAngles, at least in C#, you can’t directly set them. You have to create a new Vector3 and assign that instead.

startRotation = Random.Range(0.0, 359.0);

Vector3 rotation = transform.eulerAngles;

rotation.x = startRotation;

transform.eulerAngles = rotation;
4

So if I understand it correctly, from the Doc’s, a Vector3 is a simple struct with x,y and z floats. So in my modified code, which works now. I am generating 3 random values for each axis. These are being assigned to the Vector3 struct which is assigned to the transform.eulerAngles.

function Start () {
	var startX:float = Random.Range(25.0, 300.0);
	var startY:float = Random.Range(25.0, 300.0);
	var startZ:float = Random.Range(25.0, 300.0);
	
	transform.eulerAngles = Vector3(startX,startY,startZ);
	 Debug.Log("Fiered"+ startX);
         
}