Libgdx：为什么我的精灵没有动画？

Question

我正在使用libGDX构建一个小游戏，目前正在尝试在屏幕上显示动画。目前它只显示动画的第一帧。

我正在使用线程进行更新和渲染（这是我怀疑问题所在的地方）

public class SuperBoopers extends Game implements ApplicationListener {
public static final int V_WIDTH = 480;
public static final int V_HEIGHT = 600;
public SpriteBatch batch;
FieldScreen screen;

private PauseableThread thread;
private boolean running = false;

@Override
public void create () {
    batch = new SpriteBatch();
    screen = new FieldScreen(this);
    setScreen(screen);
    running = true;
    thread = new PauseableThread(new Runnable() {
        long timeLast = System.nanoTime();
        final double ticks = 60D;
        double ns = 1000000000 / ticks;
        float dt = 0;
        @Override
        public void run() {
            while (running){
                long timeNow = System.nanoTime();
                dt += (timeNow - timeLast)/ns;
                timeLast = timeNow;

                if(dt >= 1) {
                    update();
                    render(dt);
                }
            }
        }
    });
}

private void update(){
    screen.update();
}

public void render (float dt) {
    screen.render(dt);
}

这是动画对象的类

public class Actor {
private static Texture atlas = new Texture("Atlas.png");

private Sprite sprite;
private int frames; //number of total frames for the animation
private int frameNumber; //current frame number
private int xi; //x location of the first frame in the texture atlas
private int yi; //y location of the first frame in the texture atlas
private int frameSize; //standard size of a single square frame in pixels


public Actor(int frames, int xi, int yi){
    this.frames = frames;
    this.xi = xi;
    this.yi = yi;
    frameNumber = 0;
    frameSize = 64;
    sprite = new Sprite(new TextureRegion(atlas, xi, yi, frameSize, frameSize));
}

public void update(){
    //checks what frame it's on, if was last frame, resets frame number
    if(frameNumber == frames-1){
        frameNumber = 0;
    } else {frameNumber++;}

    //scoots the TextureRegion forward the distance of one frameSize
    sprite.setRegionX(xi+(frameSize*frameNumber));
}

public void draw(SpriteBatch batch){
    sprite.draw(batch);
}}

我知道我可能会遗漏一些非常大而且显而易见的东西。