what did function normalized do?

Question

I saw this code at docs:

...
dir = Vector3()
...
input_movement_vector = input_movement_vector.normalized()
dir += -cam_xform.basis.z.normalized() * input_movement_vector.y
...

Why can the product of input_movement_vector.y and cam_xform.basis.z be assigned(+=) to vector dir?
And, why can cam_xform.basis.z.normalized() be used? I saw *kidscancode* said “you can't normalize only the x component”.
I can't understand that.

Answer 1

You need to learn about vectors and transforms.

First, I would really recommend reading this:
https://docs.godotengine.org/en/latest/tutorials/math/vector_math.html

And then this:
http://kidscancode.org/godot_recipes/math/transforms/

"Normalizing" means setting a vector's length to 1.

transform.basis is made up of three vectors, x, y, and z, which represent the object's local coordinate axes. So basis.z is a Vector3. See Transform for details.

That said, basis vectors are already normalized, so it's not necessary to use normalized() on them.

Comments

Thank you for your answer.
But if I understand correctly, you say "basis.z" doesn't need to use "normalized()", and docs does have code like that, which means DOCS is wrong, right?

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Nobody's perfect. :)

Normalizing an already normalized vector doesn't hurt, it just doesn't do anything.

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I'll try to help modify this.(‾◡◝)
Thanks, again.