当恰好在两个正方形之间时，圆会改变方向

Question

我有一个 Box2D 世界，圆圈代表行人，正方形代表建筑物，我有一个算法可以找到最近的建筑物，然后它会在边缘转弯，但我有一个问题，它会在它正好在里面时转弯在建筑物之间，所以算法可以工作，但不是我想要的方式

def pedestrian_walk(pedestrian, buildings):
    ## Find the building nearest to the pedestrian
    list_of_distances = []
    for building in buildings:
        list_of_distances.append(np.sqrt((pedestrian.body.position[0] - building.footprint.position[0])**2 + (pedestrian.body.position[1] - building.footprint.position[1])**2))
    pedestrian.nearest_building= list_of_distances.index(min(list_of_distances))
    #print(f"Nearest builing index is: {pedestrian.nearest_building}")


    building = buildings[pedestrian.nearest_building]

    #Pedestrian walks around the left side of the nearest building
    if pedestrian.body.position[0] <= building.position[0] and  building.position[1] - building.shape[1] <= pedestrian.position[1] <= building.position[1] + 1.05*building.shape[1]:
        pedestrian.body.__SetLinearVelocity(b2Vec2(0,pedestrian.ped_velocity))
        print("1st if")
    #Pedestrian walks around the right side of the nearest building
    elif pedestrian.body.position[0] > building.position[0] and building.position[1] - building.shape[1] <= pedestrian.position[1]<= building.position[1] + 1.05*building.shape[1]:
        pedestrian.body.__SetLinearVelocity(b2Vec2(0,-pedestrian.ped_velocity))
        print("2nd if")

    #Pedestrian walks around the upper side of the nearest building
    elif pedestrian.body.position[1] > building.position[1] and building.position[0] - building.shape[0] <= pedestrian.position[0] <= building.position[0] + 1.05*building.shape[0]:
        pedestrian.body.__SetLinearVelocity(b2Vec2(pedestrian.ped_velocity,0))
        print("3rd if")
    #Pedestrian walks around the lower side of the nearest building
    elif pedestrian.body.position[1] <= building.position[1] and building.position[0] - building.shape[0] <= pedestrian.position[0] <= building.position[0] + 1.05*building.shape[0]:
        pedestrian.body.__SetLinearVelocity(b2Vec2(-pedestrian.ped_velocity,0))
        print("4th if")

我在 pygame 主游戏循环中调用函数，它工作正常：

Skyscrapers = create four buildings
while running:

...

    while k <= MAX_AMOUNT_PEDESTRIANS:
        random_skyscraper = random.choice(skyscrapers) #Randomly choose a skyscraper next to which a pedestrian is generated
        skyscraper_to_walk_around.append(random_skyscraper)
        new_walker = Pedestrian(box2world, position = (random_skyscraper.position[0] -random.randint(-random_skyscraper.shape[0],random_skyscraper.shape[0]),\
                            random_skyscraper.position[1] -random.randint(-random_skyscraper.shape[1],random_skyscraper.shape[1])))
        walkers.append(new_walker)
        positive_negative.append([-1,1][random.randrange(2)])
        k = k+1

    for ped in range(MAX_AMOUNT_PEDESTRIANS):
        pedestrian_walk(walkers[ped],skyscrapers)

如果可能的话我还有一个要求，有没有更多的"pythonic"方法可以让代码更简单或更清晰（但这是次要问题，我需要先解决转向）？非常感谢

编辑：我的代码背后的主要思想是：我有类行人和建筑物，行人是动态物体，建筑物是静态物体。我需要行人绕过最近的建筑物并穿过 "streets"（我试图在我之前的问题“Rolling a circle around a square”中找到可行的算法，您可以在其中找到我对两者的定义类。我是能解决滚动的问题，不是很完美，但是很满意

问题是，当行人试图穿过 "street" 并且恰好在两座建筑物之间的中间时，它并没有继续向前移动到第二座建筑物，而是转了 90° 并且它会 "in the middle of a road"

问题出在 if 语句中，当它更改最近的建筑参数时，它也会从假设第一个 if 跳到第三个 if...我不知道如何解决它

我尽力让自己清楚，但如果对我的代码仍有任何疑问，我可以 post 我的代码（我尽量避免这种情况，因为它不是很短的代码）

我尝试按照下面评论中的建议更改函数中最近建筑物的代码，但不幸的是，它没有用

图片：这是它现在正在做的事情的图片，我希望黄色圆圈 ("pedestrians") 在那些蓝线给定的范围内绕过那些蓝色方块 ("buildings") ("fences")。我希望行人找到他们最近的建筑物（可以正常工作）然后绕着建筑物走动，或者至少在到达最近建筑物的拐角处时转弯，但是正如您所看到的那样，行人在 "nearest_building"参数改了...清晰可见他们是走在中间a"street"...错了

Answer 1

好吧，我自己找到了答案，问题是我没有正确设置 if 语句的限制，现在可以了。我做了这个改进：

def pedestrian_walk(pedestrian, buildings):
    ## Find the building nearest to the pedestrian
    list_of_distances = []
    for building in buildings:
        list_of_distances.append(np.sqrt((pedestrian.body.position[0] - building.footprint.position[0])**2 + (pedestrian.body.position[1] - building.footprint.position[1])**2))
    pedestrian.nearest_building= list_of_distances.index(min(list_of_distances))
    #print(f"Nearest builing index is: {pedestrian.nearest_building}")

    building = buildings[pedestrian.nearest_building]
    #Pedestrian walks around either the left or right side of the nearest building
    if building.position[0] - 1.15*building.shape[0]  <=pedestrian.body.position[0] <= building.position[0] + 1.15*building.shape[0]  and  building.position[1] - building.shape[1] <= pedestrian.position[1] <= building.position[1] + 1.05*building.shape[1]:
        pedestrian.body.__SetLinearVelocity(b2Vec2(0,pedestrian.ped_velocity))
        print("1st if")

    #Pedestrian walks around either lower or upper side of the nearest building
    elif building.position[1] - 1.15*building.shape[1] <= pedestrian.body.position[1] <= building.position[1] + 1.15*building.shape[1]:
        pedestrian.body.__SetLinearVelocity(b2Vec2(-pedestrian.ped_velocity,0))
        print("2nd if")

当恰好在两个正方形之间时，圆会改变方向

A circle changes its direction when exactly between two squares

python

algorithm

if-statement

box2d