Libgdx 汽车弹跳

Question

我已经用 libgdx 创建了一辆基本的汽车，现在我正在尝试创建一个地面让它继续行驶。起初，我只是使用链形制作了一个静态夹具，其中 2 个点在两个方向上都远离屏幕。这是有效的代码。

ChainShape groundShapetest = new ChainShape();
groundShapetest.createChain(new float[]{-100, 0.1f , 10000, 0.1f});
environment.createFixture(groundShapetest, 0);
groundShapetest.dispose();

这运行良好，汽车按预期平稳移动（没有弹跳）。接下来，我想添加更多有趣的地形，并尝试使用许多背靠背设置的小链形状来建造地面。

while (last.x <= rightEdge)
{
next = GenerateTerrainContour(h, last.x);//, w/(float)num_sections);
EdgeShape groundShapetest = new EdgeShape();
groundShapetest.set(last, next);
environment.createFixture(groundShapetest, 0);
groundShapetest.dispose();
last = next;
}

GenerateTerrainContour() 只返回随机轮廓的下一个点。 当我这样做并启用汽车电机时，汽车开始随机弹跳，就好像它正在撞到什么东西或越过粗糙的地面一样。地面是完全光滑的，即使我将 GenerateTerrainContour() 的 y 分量设置为始终返回 0，它仍然如此。

我什至不确定如何调试它，因为显然有一些力影响了汽车，但我不确定它来自哪里。任何帮助将非常感激。 如果有帮助，我可以发布更多代码吗？

如果有人想尝试模拟这个，我创建了一个只有一个轮子的简单项目并给它一个扭矩。它在我创造的地面上做同样的弹跳动作。您所要做的就是将此代码复制到 libgdx 项目中，您就会明白我在说什么。我一定错过了一些简单的东西，但我不知道它是什么。

package com.mygdx.game;


import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.InputAdapter;
import com.badlogic.gdx.Input.Keys;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.physics.box2d.Body;
import com.badlogic.gdx.physics.box2d.BodyDef;
import com.badlogic.gdx.physics.box2d.Box2DDebugRenderer;
import com.badlogic.gdx.physics.box2d.ChainShape;
import com.badlogic.gdx.physics.box2d.CircleShape;
import com.badlogic.gdx.physics.box2d.Fixture;
import com.badlogic.gdx.physics.box2d.FixtureDef;
import com.badlogic.gdx.physics.box2d.World;
import com.badlogic.gdx.physics.box2d.BodyDef.BodyType;

public class groundTest extends ApplicationAdapter {


private static final float WORLD_TO_BOX = 0.01f;
private static final float BOX_TO_WORLD = 100f;
private static final float TIMESTEP = 1 / 60f;;
private static final int VELOCITYITERATIONS = 8;
private static final int POSITIONITERATIONS = 3;
private static final String TITLE = "GND_TEST";
private static final boolean DEBUG = true;
private static final int PPM = 50;
private World world;
private Box2DDebugRenderer debugRenderer;   
private OrthographicCamera camera;
private Car car;
Body lw;


@Override
public void create () {
    float w = Gdx.graphics.getWidth()/PPM;
    float h = Gdx.graphics.getHeight()/PPM;
    world = new World(new Vector2(0, -9.81f), true);

    camera = new OrthographicCamera(w, h);
    camera.update();
    createGND();
    //initCar(w,h);
    makeWheel();


    debugRenderer =  new Box2DDebugRenderer();

    }

@Override
public void resize(int width, int height) {
    camera.viewportWidth = width/PPM;
    camera.viewportHeight = height/PPM;

    camera.update();
    // camera.position.set(camera.viewportWidth/2f, camera.viewportHeight/2f, 0);
}

@Override
public void render () {
    Gdx.gl.glClearColor(0, 0, 0, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
    Gdx.graphics.setTitle(TITLE + " -- FPS: " + Gdx.graphics.getFramesPerSecond());


//  camera.position.set(car.getChassis().getPosition().x + ((float)Gdx.graphics.getWidth() / PPM)/4.0f, camera.viewportHeight/3.0f, 0);
    camera.position.set(lw.getPosition().x, 0, 0);

    camera.update();


    if(DEBUG)
    {


        //Matrix4 cameraCopy = camera.combined.cpy();
        //debugRenderer.render(world, cameraCopy.scl(BOX_TO_WORLD));
        debugRenderer.render(world, camera.combined);

    }

    world.step(TIMESTEP, VELOCITYITERATIONS, POSITIONITERATIONS);


}


private void createGND()
{
    BodyDef bodyDef = new BodyDef();
    bodyDef.type = BodyType.StaticBody;
    Body ground = world.createBody(bodyDef);

    //Uncomment the next 4 lines to get gronud that causes no bouncing
    //ChainShape groundNoBounce = new ChainShape(); 
    //groundNoBounce.createChain(new float[]{-10f, 0, 1000f, 0});
    //ground.createFixture(groundNoBounce, 0.0f).setRestitution(0); 
    //groundNoBounce.dispose();

    // comment this loop out if above uncommented
    for(int x = -10; x < 1000; x+=1)
    {
        ChainShape groundBox = new ChainShape(); 
        groundBox.createLoop(new float[]{(float)x,-3.0f, 
                                (float)x+1.0001f, -3.0f,
                                (float)x+1.0001f,0.0f, 
                                (float)x, 0.0f});

        ground.createFixture(groundBox, 0.0f).setRestitution(0); 

        groundBox.dispose();
    }
}



private void makeWheel()
{
    BodyDef bodyDef = new BodyDef();
    bodyDef.type = BodyType.DynamicBody;
    bodyDef.position.set(0, 10);

    FixtureDef wheelFixtureDef = new FixtureDef();


    wheelFixtureDef.density = 2f;
    wheelFixtureDef.friction = 50;//0.8f;
    wheelFixtureDef.restitution = 0.0f;//25f;//0.5f;            
    // 
    CircleShape wheelShape = new CircleShape();
    wheelShape.setRadius(0.5f);

    wheelFixtureDef.shape = wheelShape;

    lw = world.createBody(bodyDef);
    lw.createFixture(wheelFixtureDef).setRestitution(0.0f);

    lw.applyTorque(-3000f, true);
    camera.zoom = .25f;
    camera.update();

}
}

Answer 1

好的，我找到了解决方案。这是我使用的修复程序的链接。这有点骇人听闻，我希望 Box2d 能解决这个错误，但看起来球正在与段的边缘发生碰撞，即使它们的高度完全相同。 这对我有用。 http://www.box2d.org/forum/viewtopic.php?f=8&t=7917