如何在Python Ursina中获取鼠标位置向量并解决数组为空问题

我正在制作一个平台编辑器，需要获取鼠标位置并在该位置放置平台对象，之后要将鼠标的Vector3位置存储到数组中，以便后续转换为代码。但目前执行存储操作时，得到的是空数组。

原代码 #

from ursina import *
from ursina.prefabs.sky import Sky
from ursina.shaders import basic_lighting_shader

app = Ursina(borderless = False)

window.fullscreen = True
window.fps_counter.enabled = False

editor = EditorCamera()
camera.fov = 90

class StartPlatform(Entity):
    def __init__(self):
        super().__init__(
            parent = scene,
            model = "cube",
            position = (0, 0, 0),
            scale = (10, 2, 10),
            collider = "mesh",
            shader = basic_lighting_shader,
            texture = "white_cube",
            color = color.lime
        )

class AddPlatform(Entity):
    def __init__(self, position = (0, 0, 0)):
        super().__init__(
            parent = scene,
            model = "cube",
            position = position,
            scale = (10, 2, 10),
            collider = "mesh",
            shader = basic_lighting_shader,
            texture = "white_cube",
            color = color.azure
        )

def input(key):
    if held_keys["escape"]:
        quit()

def update():
    if held_keys["left mouse"]:
        platform= AddPlatform(position = (mouse.world_point, mouse.world_point, mouse.world_point))
        platforms = []
        for i in platforms:
            platform[i].append(platforms)
        print(platforms)

Sky()
StartPlatform()
app.run()

问题原因 #

• 数组重复初始化：platforms = []写在update()函数内部，每次鼠标点击都会重新创建空数组，之前存储的位置全部丢失。
• 位置参数错误：mouse.world_point本身就是Ursina的Vector3类型，无需拆分为三个相同值传入，这样会导致位置赋值错误。
• 存储逻辑混乱：循环空数组没有实际意义，且platform[i].append(platforms)的写法完全错误，平台对象不支持下标访问，也不该将数组本身添加进去。

修复后的代码 #

from ursina import *
from ursina.prefabs.sky import Sky
from ursina.shaders import basic_lighting_shader

app = Ursina(borderless = False)

window.fullscreen = True
window.fps_counter.enabled = False

editor = EditorCamera()
camera.fov = 90

# 全局数组存储平台位置，避免每次点击重置
platform_positions = []

class StartPlatform(Entity):
    def __init__(self):
        super().__init__(
            parent = scene,
            model = "cube",
            position = (0, 0, 0),
            scale = (10, 2, 10),
            collider = "mesh",
            shader = basic_lighting_shader,
            texture = "white_cube",
            color = color.lime
        )
        # 可选：将初始平台位置加入数组
        platform_positions.append(self.position)

class AddPlatform(Entity):
    def __init__(self, position = (0, 0, 0)):
        super().__init__(
            parent = scene,
            model = "cube",
            position = position,
            scale = (10, 2, 10),
            collider = "mesh",
            shader = basic_lighting_shader,
            texture = "white_cube",
            color = color.azure
        )

def input(key):
    if key == "escape":
        quit()
    # 用单次点击事件替代持续检测，避免重复创建平台
    if key == "left mouse down":
        # 直接传入mouse.world_point作为平台位置
        new_platform = AddPlatform(position=mouse.world_point)
        # 将新平台的位置存入数组
        platform_positions.append(new_platform.position)
        print("当前存储的平台位置：", platform_positions)

Sky()
StartPlatform()
app.run()

关键修改点 #

• 把存储位置的数组定义为全局变量，确保数据不会被重置。
• 改用input()事件处理鼠标左键单次点击，避免按住鼠标时持续创建平台和重复存储位置。
• 修正平台位置的参数传递，直接使用mouse.world_point。
• 调整存储逻辑，将新平台的position属性正确添加到数组中。

内容的提问来源于stack exchange，提问作者DonYeet46