Java-3d 碰撞检测

Question

我刚开始使用 java 3-d，我正在尝试制作一款游戏，您可以在其中跳到敌人身上以获得桥。除了碰撞检测，我知道如何为游戏做所有事情。当敌人的球碰到它时，我需要将玩家的球移开。我试图做一个看起来像这样的 id 语句。我知道我可能需要使用 WakeupOnCollisionEntry 类，但我不知道如何正确使用它来移除玩家球。我认为如果我使用 WakeupOnCollisionEntry 类与 objTrans.removeChild(sphere) 结合使用，但我不知道如何将它们结合使用。

如果您需要查看我的代码才能提供帮助，请看这里:

package Game;

import com.sun.j3d.utils.geometry.*;
import com.sun.j3d.utils.universe.*;
import java.awt.*;
import java.awt.event.*;
import javax.media.j3d.*;
import javax.swing.JFrame;
import javax.swing.Timer;
import javax.vecmath.*;

public class PAPITest extends JFrame implements ActionListener,KeyListener{
    private TransformGroup objTrans,objTrans2;
    private Transform3D trans = new Transform3D();
    private BranchGroup objRoot;
    private Sphere sphere, sphere2;
    private float x, dx, height = 0.0f, sign = 1.0f, xloc = 0.0f;
    private Timer timer;

    public BranchGroup createSceneGraph(){
        objRoot = new BranchGroup();
        objTrans = new TransformGroup();
        objTrans.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
        objRoot.addChild(objTrans);
        sphere = new Sphere(0.25f);
        sphere.setCollidable(true);
        objTrans = new TransformGroup();
        objTrans.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
        Transform3D pos1 = new Transform3D();
        pos1.setTranslation(new Vector3f(0.0f,0.0f,0.0f));
        objTrans.setTransform(pos1);
        objTrans.addChild(sphere);
        objRoot.addChild(objTrans);
        BoundingSphere bounds = new BoundingSphere
                (new Point3d(0.0,0.0,0.0),100.0);
        Color3f light1Color = new Color3f(0.2f,1.0f,1.0f);
        Vector3f light1Direction = new Vector3f(+4.0f,-7.0f,-12.0f);
        DirectionalLight light1 = new DirectionalLight
                (light1Color,light1Direction);
        light1.setInfluencingBounds(bounds);
        objRoot.addChild(light1);
        Color3f ambientColor = new Color3f(1.0f,1.0f,1.0f);
        AmbientLight ambientLightNode = new AmbientLight(ambientColor);
        ambientLightNode.setInfluencingBounds(bounds);
        objRoot.addChild(ambientLightNode);         
        return objRoot;
    }

    public BranchGroup createSceneGraph2(){
        objRoot = new BranchGroup();
        objTrans2 = new TransformGroup();
        objTrans2.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
        objRoot.addChild(objTrans2);
        sphere2 = new Sphere(0.25f);
        sphere2.setCollidable(true);
        objTrans2 = new TransformGroup();
        objTrans2.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
        Transform3D pos1 = new Transform3D();
        pos1.setTranslation(new Vector3f(0.0f,0.0f,0.0f));
        objTrans2.setTransform(pos1);
        objTrans2.addChild(sphere2);
        objRoot.addChild(objTrans2);
        return objRoot;
    }

    public PAPITest(){
        setLayout(new BorderLayout());
        setTitle("PAPI");
        setVisible(true);
        setSize(505,525);
        setResizable(false);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        GraphicsConfiguration config = SimpleUniverse.getPreferredConfiguration();
        Canvas3D c = new Canvas3D(config);
        add("Center",c);
        c.addKeyListener(this);
        c.setSize(500,500);
        timer = new Timer(100,this);
        timer.start();
        BranchGroup scene = createSceneGraph();
        BranchGroup scene2 = createSceneGraph2();
        SimpleUniverse u = new SimpleUniverse(c);
        u.getViewingPlatform().setNominalViewingTransform();
        u.addBranchGraph(scene);
        u.addBranchGraph(scene2);
        for(float i = 0; i < .10f; i++){
            x = 1.5f;
            dx = -.05f;
        }
    }

    public void keyPressed(KeyEvent e){
        if(e.getKeyChar() == 'd'){
            xloc = xloc + .1f;
        }

        if(e.getKeyChar() == 'a'){
            xloc = xloc - .1f;
        }
    }

    public void keyReleased(KeyEvent e){

    }

    public void keyTyped(KeyEvent e){

    }

    public void actionPerformed(ActionEvent e){
        height += .1f * sign;
        if(Math.abs(height * 2) >= 1)
            sign = -1.0f * sign;
        if(height < -.4f){
          trans.setScale(new Vector3d(1.0,.8,1.0));
        }else{
          trans.setScale(new Vector3d(1.0,1.0,1.0));
        }
        trans.setTranslation(new Vector3f(xloc,height - .15f,0.0f));
        objTrans.setTransform(trans);
        if(height < -.4f){
          trans.setScale(new Vector3d(1.0,1.0,1.0));
        }
        trans.setTranslation(new Vector3f(x += dx,-.7f,0.0f));
        objTrans2.setTransform(trans);
    }

    public static void main(String[] args){
        System.out.println("Program Started");
        PAPITest pt = new PAPITest();
        pt.addKeyListener(pt);
    }
}

编辑: 现在，我添加了一些我认为可以使它更准确的东西。我添加了这两种方法:

public void getSpherePosition(){
        positionX = (int) xloc;
        positionY = (int) height;
        position = positionX + positionY;
    }

    public void getSphere2Position(){
        positionX2 = (int) x;
        positionY2 = (int) -.7f;
        position2 = positionX2 + positionY2;
    }

我在 actionPerformed 方法中添加了这个:

        getSpherePosition();
        getSphere2Position();
        if(position == position2){
            System.out.println("It Worked");
        }

它有点管用，因为 It Worked 文本仅在玩家球靠近敌方球时显示，当我第一次启动程序时它也会显示。

有没有更好的方法呢？如果是这样，我该怎么做？以及如何让我的方式更准确，而不是在启动程序时直接显示文本？

我知道它变得不准确，因为我只是将三个变量加在一起，所以 position 可以等于 position2 即使玩家和敌人没有相互接触，但我不知道如何在不同的地方做方式。

Answer 1

很抱歉这么长时间才回复您。 Java3d 已经内置了一些方法，这些方法似乎已经被埋没在所有知识中最黑暗的地方。我找到了一种粗糙但有效的碰撞检测方法。

这是一个简单的代码片段，可以调用它来产生碰撞。

import java.util.Enumeration;
import javax.media.j3d.Behavior;
import javax.media.j3d.Bounds;
import javax.media.j3d.Node;
import javax.media.j3d.Shape3D;
import javax.media.j3d.WakeupCriterion;
import javax.media.j3d.WakeupOnCollisionEntry;
import javax.media.j3d.WakeupOnCollisionExit;
import javax.media.j3d.WakeupOnCollisionMovement;
import javax.media.j3d.WakeupOr;



/**
 *
 * @author sawyera.2016
 */
 public class Coll extends Behavior {
 /** The separate criteria used to wake up this beahvior. */
 protected WakeupCriterion[] theCriteria;

 /** The OR of the separate criteria. */
 protected WakeupOr oredCriteria;

 /** The shape that is watched for collision. */
  protected Shape3D collidingShape;

  /**
    * @param theShape
   *            Shape3D that is to be watched for collisions.
   * @param theBounds
   *            Bounds that define the active region for this behaviour
   */
  public Coll(Shape3D theShape, Bounds theBounds) {
   collidingShape = theShape;
   setSchedulingBounds(theBounds);
    }


  /**
   * This creates an entry, exit and movement collision criteria. These are
   * then OR'ed together, and the wake up condition set to the result.
   */
  public void initialize() {
    theCriteria = new WakeupCriterion[3];
    theCriteria[0] = new WakeupOnCollisionEntry(collidingShape);
    theCriteria[1] = new WakeupOnCollisionExit(collidingShape);
    theCriteria[2] = new WakeupOnCollisionMovement(collidingShape);
    oredCriteria = new WakeupOr(theCriteria);
    wakeupOn(oredCriteria);
  }

  /**
   * Where the work is done in this class. A message is printed out using the
   * userData of the object collided with. The wake up condition is then set
   * to the OR'ed criterion again.
   */
  public void processStimulus(Enumeration criteria) {
    WakeupCriterion theCriterion = (WakeupCriterion) criteria.nextElement();
    if (theCriterion instanceof WakeupOnCollisionEntry) {
      Node theLeaf = ((WakeupOnCollisionEntry) theCriterion)
          .getTriggeringPath().getObject();
      System.out.println("Collided with " + theLeaf.getUserData());
    } else if (theCriterion instanceof WakeupOnCollisionExit) {
      Node theLeaf = ((WakeupOnCollisionExit) theCriterion)
          .getTriggeringPath().getObject();
      System.out.println("Stopped colliding with  "
      + theLeaf.getUserData());
    } else {
      Node theLeaf = ((WakeupOnCollisionMovement) theCriterion)
      .getTriggeringPath().getObject();
  System.out.println("Moved whilst colliding with "
      + theLeaf.getUserData());
    }
    wakeupOn(oredCriteria);
  }
}

我不能完全相信这一点，我确实从网上获得了一些关于它的信息，但是我从 1.2 版的 java3d 制作了这个版本。