Unity2D中的X速度c＃

Question

I'm new to C# and Unity. I need to normalize the velocity of my player, but only in the x-direction. My current code is

void Update ()
{
if(rb2d.velocity.magnitude > maxSpeed)
    {
        rb2d.velocity = rb2d.velocity.normalized * maxSpeed;
    }

This controls all velocity. I tried

void Update ()
{
if(rb2d.velocity.x.magnitude > maxSpeed)
    {
        rb2d.velocity.x = rb2d.velocity.x.normalized * maxSpeed;
    }

But I think this was removed in Unity 5. What can I do?

Answer 1

Just divide your velocity X by the velocity's magnitude, which is essentially what normalize does.

// Make a copy of the current velocity.
Vector2 velocity = rb2d.velocity;

// Divide the x component by magnitude, equivalent to normalizing it.
velocity.x = velocity.x / velocity.magnitude;

// velocity now only has its x component normalized and y untouched
rb2d.velocity = velocity * maxSpeed;