Why exactly do people use '.Magnitude' for purposes that aren’t to get the distance between two Vector3’s?

[au_tk]

More and more often I see developers and other people using Vector3.Magnitude to represent a Vector3 as a single number instead of using it to get the distance.
e.g.

Velocity = someVector3.Magnitude
—or
Speed = someOtherVector3.Magnitude

instead of

distance = (someV3Position1 - someV3Position2).Magnitude

Please forgive me if I missed something I just simply don’t understand why you would use something meant to grab the distance for other things.

Could someone please explain?

[ellienonekomimi (ellie)]

Vectors contain two components, direction (.Unit) and magnitude (.Magnitude).
Magnitude isn’t strictly for measuring distance, it’s to measure size. Distance is a “size” between two points.
Speed is a “size” of a velocity.

[au_tk]

Hm, I think I kinda get it. Is there anything to compare this “size” to though?

[ellienonekomimi (ellie)]

Let’s say we have a car moving at a velocity of (20, 0, 0).
The magnitude, or “size” of this vector would be 20. This is a scalar value, meaning without direction.
The unit or direction of it would be (1, 0, 0). This is a value without scale.

Another way to look at it would be something like 5 miles north.
5 miles is the distance or magnitude, north is the direction.

[au_tk]

So magnitude is used instead because its easier to write than math.abs(someVector3.X)?

I understand what you mean I just don’t see that big of a difference.

[ellienonekomimi (ellie)]

A vector’s magnitude is the square root of the sum of all of it’s components squared.
magnitude = sqrt(vector.X^2 + vector.Y^2 + vector.Z^2)
I’m not saying you can’t use math.abs(someVector3.X) if you only wish to utilize that single axis, but there’s a substantial difference if you want the scale of the entire vector.