这是问这个问题的合适站点,因为到目前为止我已经两次被转到另一个站点。
我正在尝试用逼真的物理效果创建弹跳球。此刻,当球相互撞击时,它们会以与原来相同的方向弹回。现在,我已经在互联网上搜索了如何执行此操作,但是我只找到有关如何检测碰撞的内容,而不是什么之后要做。我对物理学不是很了解,难道我应该首先学习它们的主题吗?这是我想象球在现实生活中如何弹跳的图像。这是怎么运作的?
(来源:thewombatguru.nl)
而且,我的代码中有不良做法吗? (可能是,但是我学到很多东西,我喜欢它)
这是我当前的代码:
Asteroids.java
package Asteroids;
import javax.swing.*;
public class Asteroids {
public static void createAndShowGui() {
GamePanel gamePanel = new GamePanel();
JFrame frame = new JFrame("Asteroids");
frame.getContentPane().add(gamePanel);
frame.pack();
frame.setVisible(true);
frame.setResizable(false);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setLocation(2000, 50);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
GamePanel.java
package Asteroids;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
public class GamePanel extends JPanel implements ActionListener {
private final int WIDTH = 1000;
private final int HEIGHT = 1000;
Timer animationTimer;
ArrayList<Rock> rocks;
public GamePanel() {
Dimension preferredDimension = new Dimension(WIDTH, HEIGHT);
setPreferredSize(preferredDimension);
animationTimer = new Timer(10, this);
setUp();
}
public void setUp() {
rocks = new ArrayList<>();
rocks.add(new Rock(475, 1000, 0, -1));
rocks.add(new Rock(0, 500, 1, 0));
//rocks.add(new Rock(300, 270, -2, 2));
//rocks.add(new Rock(400, 315, -5, -1));
animationTimer.start();
}
@Override
public void actionPerformed(ActionEvent e) {
repaint();
for (Rock rock : rocks) {
for (Rock rockToCheck : rocks) {
if (!rock.equals(rockToCheck)) {
rock.checkForCollisionWithRocks(rockToCheck);
}
}
rock.checkForCollisionWithFrame(WIDTH, HEIGHT);
rock.setxPos(rock.getxPos() + rock.getxVelocity());
rock.setyPos(rock.getyPos() + rock.getyVelocity());
}
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
RenderingHints mainRenderingHints = new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setRenderingHints(mainRenderingHints);
for (Rock rock : rocks) {
rock.display(g2d);
}
g2d.dispose();
}
}
Rock.java
package Asteroids;
import java.awt.*;
public class Rock {
private int xPos;
private int yPos;
private int rockWidth;
private int rockHeight;
private int xVelocity;
private int yVelocity;
private int rockRadius;
private Color rockColor;
public Rock(int xPos, int yPos, int xVelocity, int yVelocity) {
this.xPos = xPos;
this.yPos = yPos;
this.xVelocity = xVelocity;
this.yVelocity = yVelocity;
rockWidth = 50;
rockHeight = rockWidth;
rockRadius = rockWidth / 2;
rockColor = new Color((int) (Math.random() * 255),(int) (Math.random() * 255),(int) (Math.random() * 255));
}
public void setxPos(int xPos) {
this.xPos = xPos;
}
public int getxPos() {
return xPos;
}
public int getRockWidth() {
return rockWidth;
}
public void setRockWidth(int rockWidth) {
this.rockWidth = rockWidth;
}
public int getRockHeight() {
return rockHeight;
}
public void setRockHeight(int rockHeight) {
this.rockHeight = rockHeight;
}
public int getyPos() {
return yPos;
}
public void setyPos(int yPos) {
this.yPos = yPos;
}
public int getxVelocity() {
return xVelocity;
}
public void setxVelocity(int xVelocity) {
this.xVelocity = xVelocity;
}
public int getyVelocity() {
return yVelocity;
}
public void setyVelocity(int yVelocity) {
this.yVelocity = yVelocity;
}
public int getRockRadius() {
return rockRadius;
}
public void setRockRadius(int rockRadius) {
this.rockRadius = rockRadius;
}
public void checkForCollisionWithRocks(Rock rock) {
int radiusOfBoth = rock.getRockRadius() + rockRadius;
int horDistance = Math.abs((rock.getxPos() + rock.getRockRadius()) - (xPos + rockRadius));
int verDistance = Math.abs((rock.getyPos() + rock.getRockRadius()) - (yPos + rockRadius));
int diagDistance = (int) Math.sqrt(Math.pow(horDistance, 2) + Math.pow(verDistance, 2));
if (diagDistance <= radiusOfBoth) {
xVelocity = -xVelocity;
yVelocity = -yVelocity;
rock.setxVelocity(-rock.getxVelocity());
rock.setyVelocity(-rock.getyVelocity());
rock.setxPos(rock.getxPos() + rock.getxVelocity());
rock.setyPos(rock.getyPos() + rock.getyVelocity());
}
}
public void checkForCollisionWithFrame(final int WIDTH, final int HEIGHT) {
if (xPos < 0) {
xVelocity *= -1;
xPos = 0;
} else if (xPos + rockWidth > WIDTH) {
xVelocity *= -1;
xPos = WIDTH - rockWidth;
}
if (yPos < 0) {
yVelocity *= -1;
yPos = 0;
} else if (yPos + rockHeight > HEIGHT) {
yVelocity *= -1;
yPos = HEIGHT - rockHeight;
}
}
public void display(Graphics2D g2d) {
g2d.setColor(rockColor);
g2d.fillOval(xPos, yPos, rockWidth, rockHeight);
}
}
任何人都可以帮忙吗?
现实生活中的物理学很棘手(重力,惯性等),但首先要使球彼此弹跳:
[当两个球撞击时,会有一个碰撞角度。幸运的是,由于它们是圆(假设),因此您可以通过找到穿过两个球的中心的直线的角度来找到入射角。然后,您要从垂直于该线的一种方式发送1个球,另一种方式发送另一种球。
有道理吗?
您可以从动量守恒定律开始。当两个物体碰撞时,总动量不会改变,您可以使用this link了解后面的计算,同时尝试预测两个物体碰撞后的轨迹。
关于您的代码,您似乎在Rock.java中缺少关键字段mass。您需要质量才能计算物体的动量,稍后您将用它来预测物体碰撞后的轨迹。
编辑:请注意,链接中的示例在一定程度上限于两个方向,在这些方向上,对象之间以180 *的距离相互碰撞。但是,通过将动量/速度矢量分解为4个方向(即0,90,180,270度),可以很容易地概括和找到碰撞后物体的速度。您必须使用向量数学来表示给定对象在4个方向上的速度。
在这里回答:还有一个不错的gif,您可以轻松地找出如何计算新速度;)Ball to Ball Collision - Detection and Handling