如何按级别创建绘图元素？

Question

输入数据格式：

obj_1 = [(x1, y1, z1, x2, y2, z2), (...),...]
obj_2 = [(x1, y1, z1, x2, y2, z2), (...),...]
etc.

https://pastebin.com/EiZZEeQR

任务是找到一种方法，根据创建函数的调用顺序在旧对象下创建新对象。在本例中，我们首先创建一个 obj_1，然后创建一个 obj_2，它将隐藏在 obj_1 之下。然后创建了 obj_3，因此该对象隐藏在第一个和第二个对象之下。

所需的输出数据 - 用于绘制绘图的所有线的坐标

也许我需要使用 shapely 库，但我不确定。

物体的形状可以是任何形状，因此仅基于圆形、三角形和直线来编写代码是不太正确的。

Answer 1

from itertools import chain

from matplotlib import pyplot as plt
from more_itertools import batched
from shapely import Point, LineString, Polygon, MultiPoint, MultiLineString
from shapely.plotting import plot_polygon, plot_line, plot_points

像 OP 给出的文件中那样声明对象：

obj_1 = [(0.3931383333340818, 1.1771275460626884, 0.0, 

将数据解析为有形状的对象：

shapely_objects = []
for obj in chain(obj_3, obj_1, obj_2):
    n = len(obj) / 3
    if n == 0:
        continue
    elif n == 1:
        geom = Point(obj[0])
    else:
        data = list(batched(obj, 3, strict=True))
        geom = LineString(data)
        if geom.is_ring:
            geom = Polygon(data)
    shapely_objects.append(geom)

实际处理：

def overlay(geometries: Iterable[BaseGeometry]):
    """
    Overlay shapely geometries: cut away the part of shapes that are underneath others.

    First features in input will be underneath, last feature will not be cut.
    """
    result = []
    s = set()
    tree = STRtree(geometries)
    for idx, current_feature in enumerate(geometries):
        s.add(idx)
        overlapping_features = tree.geometries.take(list(set(tree.query(current_feature)) - s))
        cut = current_feature.difference(unary_union(overlapping_features))
        result.append(cut)
    return result

shapes_overlain = overlay(shapely_objects)

可视化：

fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(8, 4), sharex=True, sharey=True)
for shape in shapely_objects:
    if isinstance(shape, Polygon):
        plot_polygon(shape, color="w", add_points=False, ax=ax1)
    elif isinstance(shape, LineString):
        plot_line(shape, color="w", add_points=False, ax=ax1)
    else:
        plot_points(shape, color="w", add_points=False, ax=ax1)

for shape in shapes_overlain:
    if isinstance(shape, Polygon):
        plot_polygon(shape, color="w", add_points=False, ax=ax2)
    elif isinstance(shape, (MultiLineString, LineString)):
        plot_line(shape, color="w", add_points=False, ax=ax2)
    elif isinstance(shape, (Point, MultiPoint)):
        plot_points(shape, color="w", add_points=False, ax=ax2)
    else:
        raise ValueError(f"shape: {shape}")


ax1.set(facecolor="#242c34", xticks=[], yticks=[])
ax2.set(facecolor="#242c34", xticks=[], yticks=[])
ax1.set_title("Normal")
ax2.set_title("Overlain")
plt.show()