如何使物体自行移动以避免与其他物体发生碰撞

Question

我做这个游戏是为了躲避来自不同方向的物体。我试图实现的是让这个对象(由计算机控制的“player”类)能够像用户控制的播放器那样躲闪。

我已经尝试使用pygame提供的基本冲突处理(当然，阅读一些关于它是如何工作的文档，以及我可以做什么来解决问题)。我所做的基本上是检查一个物体的右直角位置是否与‘玩家’的左直角重叠，反之亦然，因此它向相反的方向移动以避免碰撞。

TITLE = "Dodging-IA Attempt";
WIDTH = 320; HEIGHT = 400;
FPS = 60;

BLACK = (0,0,0); WHITE = (255,255,255);
RED = (255,0,0); GREEN = (0,255,0); BLUE = (0,0,255);

import pygame as pg;
import random, math;

class Game():
    def __init__(self):
        self.screen = pg.display.set_mode((WIDTH,HEIGHT));
        self.clock = pg.time.Clock(); self.dt = FPS/1000;
        self.running = True;
        self.all_sprites = pg.sprite.Group();
        self.bullets = pg.sprite.Group();
        self.other_sprites = pg.sprite.Group();

        self.player = Player(); self.all_sprites.add(self.player);
        self.bullet_spawn = BulletSpawn(); self.other_sprites.add(self.bullet_spawn);


class Player(pg.sprite.Sprite):
    def __init__(self):
        pg.sprite.Sprite.__init__(self);
        self.image = pg.Surface((16,32)); self.image.fill(GREEN);
        self.rect = self.image.get_rect();
        self.rect.centerx = WIDTH//2;
        self.rect.y = HEIGHT*3//4;
        self.vx = self.vy = 300;

    def update(self,dt):
        pass;

class Bullet(pg.sprite.Sprite):
    def __init__(self,x):
        pg.sprite.Sprite.__init__(self);
        self.image = pg.Surface((16,16)); self.image.fill(RED);
        self.rect = self.image.get_rect();
        self.rect.centerx = x;
        self.rect.bottom = 0;
        self.vy = 70;

    def update(self,dt):
        self.rect.y += self.vy * dt;
        if self.rect.top > HEIGHT:
            self.kill();

class BulletSpawn(pg.sprite.Sprite):
    def __init__(self):
        pg.sprite.Sprite.__init__(self);
        self.image = pg.Surface((1,1)); self.rect = self.image.get_rect();
        self.new_bullet = pg.time.get_ticks();

    def update(self):
        now = pg.time.get_ticks();
        if now - self.new_bullet > 500:
            self.new_bullet = now;
            for i in range(5):
                bullet = Bullet(random.randint(8,WIDTH-8));
                game.bullets.add(bullet);
                game.all_sprites.add(bullet);

pg.init();
pg.display.set_caption(TITLE);

game = Game();

while game.running:

    game.dt = game.clock.tick(FPS)/1000;

    for event in pg.event.get():
        if event.type == pg.QUIT:
            game.running = False;

    hits = pg.sprite.spritecollide(game.player,game.bullets,False)
    for hit in hits:
        if hit.rect.right > game.player.rect.left:  #dodge moving to left
            game.player.rect.x += game.player.vx*game.dt
            print("DODGED TO LEFT")
        if hit.rect.left < game.player.rect.right:  #dodge moving to right
            game.player.rect.x -= game.player.vx*game.dt
            print("DODGED TO RIGHT")


    game.all_sprites.update(game.dt);
    game.other_sprites.update();

    game.screen.fill(BLUE);
    game.all_sprites.draw(game.screen)
    game.other_sprites.draw(game.screen)
    pg.display.flip();

pg.quit();

因此，“玩家”总是向一个和唯一的一个方向移动，不管它是否在它的路径上碰撞，而不是实际上水平地避开掉下的物体。我能做什么才能得到这个？也许我得重新描述一下碰撞的条件？非常感谢你抽出时间。

Answer 1

检查框边是否在播放器的范围内是这样做的一种方法。如果您使检查包括在内，玩家应该回避，即使只有边缘是对齐的。

if hit.rect.right >= game.player.rect.left and hit.rect.left <= game.player.rect.left:
    game.player.rect.x += game.player.vx*game.dt
    print("DODGED TO LEFT")
elif hit.rect.left <= game.player.rect.right and hit.rect.right >= game.player.rect.right:
    game.player.rect.x -= game.player.vx*game.dt
    print("DODGED TO RIGHT")

Answer 2

无论球员和子弹在碰撞时刻的位置如何，bullet.rect.right总是比player.rect.left多，bullet.rect.left总是小于player.rect.right。如果你在纸上画画，你就会看到它。这里最好检查移动侧推杆中心。这段代码：

        if hit.rect.right > game.player.rect.left:  #dodge moving to left
            game.player.rect.x += game.player.vx*game.dt
            print("DODGED TO LEFT")
        if hit.rect.left < game.player.rect.right:  #dodge moving to right
            game.player.rect.x -= game.player.vx*game.dt
            print("DODGED TO RIGHT")

你可以改变它：

        if hit.rect.center > game.player.rect.center:
            game.player.rect.x -= game.player.vx*game.dt
        elif hit.rect.center < game.player.rect.center:
            game.player.rect.x += game.player.vx*game.dt

你可以做一些优化来缓解抽搐，但我认为错误的本质是显而易见的。