Local direction problem. Setting the rotation of a object relative to its parent.

Unity Engine
1

Hello there.

I have a simple object (transform var turbine), and i want it to smoothly face local directions, as it’s a child of the “jet” transform.
Here is the piece of code (attached to its parent “jet”):

But it doesn’t work.

Can someone help?

Also, is -Vector3.up the inverse of its absolute? I mean, live Vector3.down?

Thanks.

2

I’m not sure what you’re trying to do exactly, but it might be Transform.localRotation that you want to be modifying, rather than Transform.rotation.

Also, this:

Quaternion.LookRotation(transform.up)

Is likely to produce invalid results (since the input vector is parallel to the default reference vector).

-Vector3.up is the ‘opposite’ of Vector3.up, yes.

3

What i’m trying to do is quite simple:

There are 3 directions possible for the “turbine” transform that is child of the “jet” transform. The directions are relative to it’s parent. I want to set these directions. But nothing that i’ve tried work.

Thank you.

449484--15671--$jetty.jpg

4

I made some suggestions earlier - did those make any difference? If you changed your code at all, can you post the revised code?

5

Yes, your tip actually helped a lot. I was able to write a piece of code that actually works:

function TurnRight () {
turbine.localRotation = Quaternion.Slerp(turbine.localRotation, Quaternion(0,0,0.7,-1), 0.1);
}

function TurnLeft () {
turbine.localRotation = Quaternion.Slerp(turbine.localRotation, Quaternion(0,0,0.7,1), 0.1);
}

function Center(){
turbine.localRotation = Quaternion.Slerp(turbine.localRotation, Quaternion(0,0,0,1), 0.1);
}

However, I don’t know if it’s “okay” to use it because it’s pretty confusing and Unity manual said that it isn’t a good thing to manipulate quaternions.

Thank you.

6

Yeah, constructing the quaternions manually like that probably isn’t what you want to do. For one thing, the first two quaternions there aren’t unit-length (although the end result will likely be unit-length, as Unity generally keeps quaternions normalized ‘under the hood’). Also, although sometimes constructing a quaternion manually can produce sort-of-intuitive results, keep in mind that the elements of a rotation quaternion are not angles. (You can however use Quaternion.Euler() to create a quaternion from a set of Euler angles.)

7

turbine.localRotation = Quaternion.Slerp(turbine.localRotation, Quaternion.Euler(0,0,75), 0.1);

SOLVED.

Thank you very much Jesse Anders!