我是一个初学者，正在关注android studio中编写飞扬的小鸟的教程。我对以下代码有2个问题。鸟的第一帧下降10像素（= GRAVITY）。然后，将帧数量乘以每帧10个像素，这样他每帧下降得更快。但是，velocity.scl（1 / dt）的用途是什么？我也可能理解错了吗？为什么下降看起来很平稳？我希望它看起来更震撼，因为小鸟每帧移动很多像素。

    if(position.y>0){
        velocity.add(0,GRAVITY,0); // bird falls 15 pixels above ground
    }

    velocity.scl(dt); //multiply gravity with dt (frame) -> gravity gets larger
    position.add(0,velocity.y,0);

    if(position.y<0){
        position.y=0; // bird doesn't fall through ground
    }

    velocity.scl(1/dt); // what does this do

全鸟类：

private static final int GRAVITY = -10;
private Vector3 position;
private Vector3 velocity;
private Texture bird;

public Bird(int x,int y){
    position = new Vector3(x,y,0);
    velocity=new Vector3(0,0);
    bird = new Texture("flappy-midflap.png");
}

public void update(float dt){
    if(position.y>0){
        velocity.add(0,0);

    if(position.y<0){
        position.y=0; // bird doesn't fall through ground
    }

    velocity.scl(1/dt); // what does this do
}

public void jump(){
    velocity.y = 250;
}

public Vector3 getPosition() {
    return position;
}

public Texture getTexture() {
    return bird;
}