什么是 bpy.context.active_object 以及 Blender 的其余 API 如何使用它？

Question

我写了一个简单的脚本来制作一些球体并使用布尔运算符将它们组合成一个网格，但我不明白它是如何工作的：

import bpy
import math

# Can't run this in edit mode
if bpy.context.active_object is not None:
    bpy.ops.object.mode_set(mode='OBJECT')

# Make sure nothing is selected
for object in bpy.context.selected_objects:
    object.select_set(False)

# Remove old object. Old meshes remain in memory, but won't be saved
if 'Sad Scorpion Attempt' in bpy.data.objects:
    bpy.data.objects['Sad Scorpion Attempt'].select_set(True)
    bpy.ops.object.delete()

# Actual mesh building goes here
bpy.ops.mesh.primitive_uv_sphere_add(radius=1, location=(0, 30, 0), scale=(1.5, 2, 
1))
base = bpy.context.active_object
base.name = 'Sad Scorpion Attempt' # Object name
base.data.name = 'Sad Scorpion Attempt' # Mesh name
for i in range(6):
    bpy.ops.mesh.primitive_uv_sphere_add(radius=1, location=(-4*math.sin(math.pi*i/6), 30, 4 + 4*math.cos(math.pi*i/6)), scale=(1.5, 1.4 + 0.1*i, 1))
    new_object = bpy.context.active_object
    
    # Sets bpy.context.active_object
    bpy.context.view_layer.objects.active = base
    
    booly = base.modifiers.new(name='booly', type='BOOLEAN')
    booly.object = new_object
    booly.operation = 'UNION'
    bpy.ops.object.modifier_apply(modifier='booly')
    
    # .delete() doesn't use the current value of bpy.context.active_object, so
    # it deletes new_object instead of base
    bpy.ops.object.delete()

特别是：

• 为什么

  bpy.context.active_object

  通过分配给

  bpy.context.view_layer.objects.active

  而不是通常只分配给

  bpy.context.active_object

  来设置？
• 为什么

  bpy.ops.object.delete()

  使用

  bpy.context.active_object

  的前一个值，而

  bpy.ops.object.modifier_apply()

  使用当前值？

我试图在 Blender 文档中找到它如何工作的解释，但我发现的

bpy.context

的唯一文档是https://docs.blender.org/api/current/bpy.context.html ，甚至根本没有列出

bpy.context.active_object

！